[go: up one dir, main page]

WO2025011972A1 - Photoisomérisation de géranial et de neral - Google Patents

Photoisomérisation de géranial et de neral Download PDF

Info

Publication number
WO2025011972A1
WO2025011972A1 PCT/EP2024/068132 EP2024068132W WO2025011972A1 WO 2025011972 A1 WO2025011972 A1 WO 2025011972A1 EP 2024068132 W EP2024068132 W EP 2024068132W WO 2025011972 A1 WO2025011972 A1 WO 2025011972A1
Authority
WO
WIPO (PCT)
Prior art keywords
neral
geranial
light
pure
enriched
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
PCT/EP2024/068132
Other languages
English (en)
Inventor
Bernd Schaefer
Mathias SCHELWIES
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
BASF SE
Original Assignee
BASF SE
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by BASF SE filed Critical BASF SE
Publication of WO2025011972A1 publication Critical patent/WO2025011972A1/fr
Pending legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C45/00—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds
    • C07C45/61—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds by reactions not involving the formation of >C = O groups
    • C07C45/67—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds by reactions not involving the formation of >C = O groups by isomerisation; by change of size of the carbon skeleton
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C29/00—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom not belonging to a six-membered aromatic ring
    • C07C29/17—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom not belonging to a six-membered aromatic ring by hydrogenation of carbon-to-carbon double or triple bonds
    • C07C29/172—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom not belonging to a six-membered aromatic ring by hydrogenation of carbon-to-carbon double or triple bonds with the obtention of a fully saturated alcohol
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C29/00—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom not belonging to a six-membered aromatic ring
    • C07C29/56—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom not belonging to a six-membered aromatic ring by isomerisation
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C45/00—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds
    • C07C45/61—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds by reactions not involving the formation of >C = O groups
    • C07C45/62—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds by reactions not involving the formation of >C = O groups by hydrogenation of carbon-to-carbon double or triple bonds

Definitions

  • the present invention relates to a method, comprising the isomerization of neral of formula r the isomerization of geranial to neral, characterized in that (a) the isomerization is accomplished by irradiation with light.
  • the method according to the present invention makes it possible to convert an undesired isomer, which is an unavoidable by-product generated during the production of neral and/or geranial, into a desired isomer highly efficiently, thus greatly improving the economic performance of the method for producing the desired isomer (in high yield by expending as few energy as possible and with avoiding possible side products).
  • CN107879914A relates to a method for preparing neral by efficiently rectifying citral which comprises the following steps: the citral containing two isomers neral and geranial is rectified and separated by a rectifying tower, and a neral product is obtained at the tower top of the rectifying tower, wherein iodine and phosphorus catalytic active centers are loaded on a stripping section filler of the rectifying tower, so that a material which flows through the tower bottom and is rich in geranial is catalytically converted into a material with an increased neral proportion.
  • CN112125782A relates to a method for preparing high-purity nerol and geranial by hydrogenating citral which is characterized by comprising the steps of selectively carrying out catalytic hydrogenation reaction on nerol in citral to obtain nerol by adopting a novel transition metal composite catalyst, carrying out no catalytic reaction on geranial, and carrying out rectification separation on reaction products to obtain the high-purity nerol and geranial; wherein, the novel transition metal composite catalyst comprises a transition metal compound and a chiral spiro bisoxazoline ligand with a spiro indane skeleton.
  • RU2579122 relates to a method of obtaining the geranial from the mixture of isomers of geranial and neral (citral), based on conducting of the transformations of citral in the presence of acid catalysts, preferably montmorillonite clay, wherein the isolation of geranial from the reaction mixture can be achieved by column chromatography or distillation at reduced pressure.
  • acid catalysts preferably montmorillonite clay
  • CN116474824A relates to a catalyst for isomerising neral to geranial, characterized in that: the catalyst is one or more of citric acid, tartaric acid, amino acid and malic acid and a method for increasing the geranial content in citral, which comprises adding the catalyst to citral.
  • Citral under light irradiation decreased rapidly with Z-E isomerization and new peaks, such as I, II and III appeared (page 464, column 2, paragraph 6 and page 465, column 1 , paragraph 2 and Fig. 1).
  • Citral in ethanol was irradiated by UV light under nitrogen, wherein products 3 to 12 shown in Fig. 2 are obtained.
  • An object is to provide a method for efficiently obtaining neral, or geranial.
  • the present invention relates to a method, comprising the isomerization of neral of formula citral B (cis form)) to geranial of formula citral A (trans form)), or the isomerization of geranial to neral, characterized in that (a) the isomerization is accomplished by irradiation with light.
  • the present invention relates to a method for isomerization of neral of formula (II; citral B (cis form)) to geranial of formula (I; citral A (trans form)), or the isomerization of geranial to neral, characterized in that (a) the isomerization is accomplished by irradiation with light.
  • the present invention relates to producing a desired isomer (real or geranial), comprising the isomerization of neral of formula (II; citral B (cis form)) to geranial of formula (I; citral A (trans form)), or the isomerization of geranial to neral, characterized in that (a) the isomerization is accomplished by irradiation with light.
  • the method is a method for producing a desired isomer, in particular neral or geranial, optionally comprised in a mixture comprising neral and geranial.
  • the method of the present invention may be a method for the preparation of enriched or pure neral and/or geranial.
  • the produced that produced neral may either be pure neral or may be enriched neral, i.e., neral comprised in a mixture that further comprises geranial and optionally one or more further components that has a higher neral content as the mixture before isomerization (of step a)).
  • the produced that produced geranial may either be pure geranial or may be enriched geranial, i.e., geranial comprised in a mixture that further comprises neral and optionally one or more further components that has a higher geranial content as the mixture before isomerization (of step a)).
  • irradiation with light is irradiation with monochromatic light.
  • step a) the geranial is irradiated with monochromatic light, or in step a) the neral is irradiated with monochromatic light.
  • the irradiation of geranial does not exclude the concomitant irradiation of neral and vice versa, in particular when a mixture consisting of or comprising both, neral and geranial, is irradiated.
  • Irradiation of neral may be irradiation of pure neral or of a mixture consisting of or comprising both, neral and geranial, in particular enriched neral (i.e., a mixture comprising a higher content of neral).
  • One or more irradiations may lead to an altered, preferably more desirable, ratio of neral : geranial.
  • the method of the present invention is for increasing the content of neral in a composition, in particular a mixture comprising geranial and neral, comprising the step a) isomerization of the enriched or pure geranial to a mixture of neral and geranial by irradiation with light.
  • the method of the present invention is for increasing the content of geranial in a composition, in particular a mixture comprising geranial and neral, comprising the step a) isomerization of the enriched or pure neral to a mixture of neral and geranial by irradiation with light.
  • monochromatic light is all radiation at least 90 % of its power and at most 100 % thereof being emitted in the range from 350 nm to 490 nm, i.e. at least 90 % and at most 100 % of the radiant flux of the monochromatic light is emitted in the range from 350 nm to 490 nm.
  • Its monomodal emission spectrum preferably exhibiting a halfwidth of not more than +/- 100 nm, preferably not more than +/- 60 nm, such as +/- 10 to +/- 30 nm, in relation to the wavelength of the emission maximum.
  • monochromatic light is all radiation at least 90 % of its power and at most 100 % thereof being emitted in the range from 300 nm to 420 nm, i.e. at least 90 % and at most 100 % of the radiant flux of the monochromatic light is emitted in the range from 300 nm to 420 nm.
  • Its monomodal emission spectrum preferably exhibiting a halfwidth of not more than +/- 100 nm, preferably not more than +/- 60 nm, such as +/- 10 to +/- 30 nm, in relation to the wavelength of the emission maximum.
  • Said defined halfwidth gives a highly structured lighting profile, which results in an improved yield of neral/geranial.
  • the method according to the present invention makes it possible to convert an undesired isomer, which is an unavoidable by-product generated during the production of neral and/or geranial, into a desired isomer highly efficiently, thus greatly improving the economic performance of the method for producing the desired isomer (in high yield by avoiding cost intensive distillation and with avoiding possible side products).
  • the method of the present invention is commercially attractive as it enables the efficient, demand-oriented production of either neral, or geranial and, hence, offers more flexibility in the production of aroma chemicals.
  • the present invention enables the efficient production of neral, or geranial.
  • the present invention relates to
  • a method for the preparation of enriched or pure neral comprising the steps a) the isomerization of the enriched or pure geranial to a mixture of neral and geranial by irradiation with light; b) the separation, especially the (continuous) separation of the mixture comprising geranial and neral obtained in step a) to give the product, enriched or pure neral, and enriched or pure geranial; and c) optionally recycling of the enriched or pure geranial obtained in step b) to step a).
  • N.3 The method according to embodiments N.1 , or N.2, wherein in step a) a solution of the geranial in a solvent is irradiated with light.
  • N.4 The method according to embodiment N.3, wherein the solvent is selected from water, dichloromethane, trichloromethane, tetrachloromethane, CS2, Ci- C4alcohols, chlorobenzene, fluorobenzene, trifluoromethylbenzene, acetonitrile, dimethylformamide (DMF), dimethylsulfoxide (DMSO), tetra hydrofuran (THF), ethylacetate, acetone and mixtures thereof.
  • the solvent is selected from water, dichloromethane, trichloromethane, tetrachloromethane, CS2, Ci- C4alcohols, chlorobenzene, fluorobenzene, trifluoromethylbenzene, acetonitrile, dimethylformamide (DMF), dimethylsulfoxide (DMSO), tetra hydrofuran (THF), ethylacetate, acetone and mixtures thereof.
  • DMF dimethylform
  • step a) The method according to any of embodiments N.1 to N.4, wherein in step a) the geranial is irradiated with light in the presence of a sensitizer.
  • N.6 The method according to embodiment G.5, wherein the sensitizer is selected from [lr(dF(CF 3 )ppy) 2 (bpy)]PF 6 , (lr[dF(CF 3 )ppy]2(dtbbpy))PF 6 , (lr[dF(CF 3 )ppy] 2 (dtbpy))PF 6 , (lr[dF(Me)ppy] 2 (dtbbpy))PF 6 , [lr(dtbbpy)(ppy) 2 ]PF 6 , lr(ppy) 3 , Ru(bpy) 3 CI 3 , [Ru(bpy) 3 ](PFe)2, benzophenone, thioxanthen-9-one, Michler's Ketone, tetramethoxy- antracen-9-one, diacetyl-4,5-bis(carbazol-9-yl)-1 ,2-dicyanobenzene (2CzPN), 3, 4,5
  • N.7 The method according to embodiments N.5, or N.6, wherein in step a) the geranial is irradiated with monochromatic light in the wavelength range of 350 to 490 nm.
  • step a) The method according to embodiments N.1 , or N.2, wherein in step a) the geranial in neat form is irradiated with light, i.e. no solvent and sensitizer are present.
  • step a) The method according to embodiment N.8, wherein in step a) the geranial is irradiated with monochromatic light in the wavelength range of 300 to 420 nm.
  • step a) is done in a temperature range of -20 to 100 ° C.
  • step a) is done in a pressure range from 1 mbar to 20 bar.
  • step a) is carried out in a continuously stirred reaction vessel, in a pumping circuit, or in a continuous flow reactor.
  • N.13 The method according to any of the preceding embodiments, wherein the irradiation with light is accomplished by use of at least one LED (light emitting diode), or laser.
  • N.14 The method according to any of the preceding embodiments, which is a method for producing menthol and comprises the additional steps d.1) to g.1): d.1) catalytic hydrogenation of neral obtained by the method of the present invention (e.g., according to any of claims 1-3, 6-16, 18-23), preferably of the neral obtained in any of steps 0), a) and/or b) (e.g., 0) and/or b), or a) and/or b)), to give citronellal, e.1) cyclization of citronellal to give isopulegol in the presence of an acidic catalyst, f.1) optionally purification of isopulegol, preferably by crystallization and g.1) catalytic hydrogenation of isopulegol to
  • N.15 The method according to embodiment N.14, comprising the additional steps d.2) to g.2): d.2) asymmetric catalytic hydrogenation of neral obtained by the method of the present invention (e.g., according to any of claims 1-3, 6-16, 18-23), preferably of the neral obtained in any of steps 0), a) and/or b) (e.g., 0) and/or b), or a) and/or b)), to give optically active citronellal, e.2) cyclization of optically active citronellal to give optically active isopulegol in the presence of an acidic catalyst, f.2) optionally purification of optically active isopulegol, preferably by crystallization and g.2) catalytic hydrogenation of optically active isopulegol to give optically active menthol.
  • asymmetric catalytic hydrogenation of neral obtained by the method of the present invention e.g., according to any of claims
  • the photochemical isomerisation of geranial advantageously leads to a mixture of neral and geranial, in which neral is present in an amount of more than 50% the amount of geranial.
  • G.1 a method for the preparation of enriched or pure geranial, comprising the steps a) the isomerization of the enriched or pure neral to a mixture of neral and geranial by irradiation with light; b) the separation, especially the (continuous) distillative separation of the mixture comprising geranial and neral obtained in step a) to give the product, enriched or pure geranial, and enriched or pure neral; and c) optionally recycling of the enriched or pure neral obtained in step b) to step a).
  • G.3 The method according to embodiments G.1 , or G.2, wherein in step a) a solution of the neral in a solvent is irradiated with light.
  • G.4 The method according to embodiment G.3, wherein the solvent is selected from water, dichloromethane, trichloromethane, tetrachloromethane, CS2, Ci- C4alcohols, chlorobenzene, fluorobenzene, trifluoromethylbenzene, acetonitrile, dimethylformamide (DMF), dimethylsulfoxide (DMSO), tetra hydrofuran (THF), ethylacetate, acetone and mixtures thereof.
  • the solvent is selected from water, dichloromethane, trichloromethane, tetrachloromethane, CS2, Ci- C4alcohols, chlorobenzene, fluorobenzene, trifluoromethylbenzene, acetonitrile, dimethylformamide (DMF), dimethylsulfoxide (DMSO), tetra hydrofuran (THF), ethylacetate, acetone and mixtures thereof.
  • DMF dimethylform
  • G.5 The method according to any of embodiments G.1 to G.4, wherein in step a) the neral is irradiated with light in the presence of a sensitizer.
  • G.7 The method according to embodiments G.5, or G.6, wherein in step a) the neral is irradiated with monochromatic light in the wavelength range of 350 to 490 nm.
  • G.8 The method according to embodiment G.7, or G.8, wherein in step a) the neral in neat form is irradiated with light, i.e. no solvent and sensitizer are present.
  • step a) is done in a temperature range of -20 to 100 ° C.
  • step a) is done in a pressure range from 1 mbar to 20 bar.
  • step a) is carried out in a continuously stirred reaction vessel, in a pumping circuit, or in a continuous flow reactor.
  • G.13 The method according to any of the preceding embodiments, wherein the irradiation with light is accomplished by use of at least one LED (light emitting diode), or laser.
  • G.14 The method according to any of the preceding embodiments, which is a method for producing linalool and comprises the additional steps d’) and e’): d’) catalytic hydrogenation of geranial and/or neral obtained by the method of the present invention, preferably of geranial obtained by the method of the present invention,, in particular of geranial obtained in any of steps 0), a) and/or b) (e.g., 0) and/or b), or a) and/or b)), especially catalytic hydrogenation of the geranial obtained in any of steps 0), a) and/or b) (e.g., 0) and/or b), or a) and/or b)) in the presence of a supported ruthenium, r
  • the present invention is directed to a method for the preparation of enriched or pure neral, comprising the step a) the isomerization of the enriched or pure geranial to a mixture of neral and geranial by irradiation with light.
  • Distillative means for partly or completely separating neral and geranial from one another, in other words enriching either neral in a fraction and/or geranial in a fraction may be conducted by any means suitable for this purpose. Examples for suitable distillation steps are taught in W02009/068444.
  • the present invention is directed to a method for the preparation of enriched or pure neral, comprising the steps
  • the mixture comprising geranial and neral obtained in step a) is preferably distillatively separated to give, the product, enriched or pure neral and enriched or pure geranial, which is recycled to step a).
  • the distillative separation is preferably a continuous distillative separation.
  • the present invention is directed to a method for the preparation of enriched or pure neral, comprising, preferably continuously, the steps a) the isomerization of the enriched or pure geranial to a mixture of neral and geranial by irradiation with light; b) the continuous distillative separation of the mixture comprising geranial and neral obtained in step a) to give the product, enriched or pure neral, and enriched or pure geranial; and c) optionally recycling of the enriched or pure geranial obtained in step b) to step a).
  • the term “product, enriched or pure geranial, and enriched or pure neral” may be understood as at least two separated streams: a first stream that is enriched or pure neral and a second stream that is enriched or pure geranial.
  • the first stream that is enriched or pure geranial may preferably be considered as the desired product and the second product as side product that may optionally be recycled (e.g., in step c)).
  • the present invention is directed to a method for the preparation of enriched or pure neral, comprising, preferably continuously, the steps 0) the distillative separation of mixtures comprising geranial and neral to give enriched or pure geranial and neral; a) the isomerization of the enriched or pure geranial obtained in step 0) to a mixture of neral and geranial by irradiation with light; b) the continuous distillative separation of the mixture comprising geranial and neral obtained in step a) to give the product, enriched or pure neral, and enriched or pure geranial; and c) optionally recycling of the enriched or pure geranial obtained in step b) to step a).
  • the present invention is directed to a method for the preparation of enriched or pure geranial, comprising the step a) the isomerization of the enriched or pure neral to a mixture of neral and geranial by irradiation with light.
  • the enriched or pure geranial is preferably provided by distillative separation of mixtures comprising geranial and neral.
  • the present invention is directed to a method for the preparation of enriched or pure geranial, comprising the steps
  • the present invention is directed to a method for the preparation of enriched or pure geranial, comprising, preferably continuously, the steps a) the isomerization of the enriched or pure neral to a mixture of neral and geranial by irradiation with light; b) the distillative separation of the mixture comprising geranial and neral obtained in step a) to give the product, enriched or pure geranial, and enriched or pure neral; and c) optionally recycling of the enriched or pure neral obtained in step b) to step a).
  • Suitable feed materials in step 0) are substance mixtures which comprise neral and geranial, preferably those which consist predominantly of the double-bond isomers neral and geranial.
  • substance mixtures which comprise at least 90% by weight to 100% by weight, particularly preferably at least 95 to 98% by weight (in each case based on the total amount of the respective substance mixture) of geranial and neral or consist thereof in the specified fractions and in addition can comprise to a low extent, i.e. in a fraction of up to 10% by weight, preferably up to 5% by weight (in each case based on the total amount of the respective substance mixture) also further components such as, for example, isomers, by-products or impurities.
  • One preferred feed material is synthetically produced citral, especially that which has been obtained by thermal cleavage of 3-methyl-2- buten-1-al diprenylacetal with elimination of prenol to give cis/trans-prenyl (3- methylbutadienyl) ether, Claisen rearrangement thereof to give 2,4,4-trimethyl-3-formyl-1,5- hexadiene and subsequent Cope rearrangement thereof, as described, for example, in EP992477 and European patent application no. 23177047.0. This comprises typically about 45 to about 55% by weight of neral as well as about 55 to about 45% by weight and about 1 to 5% by weight of further compounds and/or impurities.
  • the method according to the invention comprises, as additional inserted step, the aforementioned production method of citral starting from 3-methyl-2-buten-1-al diprenylacetal.
  • a substance mixture which is used in step 0) consists preferably of 30 to 70% by weight, preferably of 40 to 60% by weight, of neral, of 70 to 30% by weight, preferably of 60 to 40% by weight, of geranial and of 0 to 5% by weight of further components, where the percentages add up to 100% by weight.
  • the method according to the invention comprises, as step 0), the distillative separation of the geranial- and neral-containing mixtures to give enriched or pure geranial or neral.
  • step 0 the distillative separation of the geranial- and neral-containing mixtures to give enriched or pure geranial or neral.
  • distillative separation of geranial- and neral-containing mixtures can be carried out advantageously by means of a dividing wall column or an interconnection of thermally coupled columns.
  • neral in particular is accessible in pure or enriched form through distillative separation of substance mixtures comprising geranial and neral.
  • a continuous method for producing neral in pure or enriched form by distillative removal of neral from substance mixtures comprising neral and geranial is inserted, the distillative removal being carried out in a dividing wall column or in an interconnection of two distillation columns in the form of a thermal coupling having 80 to 200 theoretical plates and one or more side take-off points at an absolute operating pressure of from 5 to 200 mbar.
  • the distillative removal is usually carried out by separating the neral and geranial comprising substance mixture used into, in each case, one or more low-boiling, medium-boiling and high-boiling fraction or fractions, and removing neral in pure or enriched form as maximmboiling fraction at the side take-off point of the dividing wall column used or the interconnection of two distillation columns in the form of a thermal coupling in liquid or gaseous form.
  • the distillative separating is preferably a continuous method for isolating neral in pure or enriched form by distillative removal of neral from substance mixtures comprising neral and geranial, the distillative removal being carried out in a dividing wall column or in an interconnection of two distillation columns in the form of a thermal coupling having 80 to 200 theoretical plates and one or more side take-off points at an absolute operating pressure, i.e. at an absolute pressure in the dividing wall column or the interconnection of two distillation columns in the form of a thermal coupling of from 5 to 200 mbar.
  • the dividing wall column has 80 to 200, preferably 100 to 180, theoretical plates and one or more, preferably 1 to 3, particularly preferably 1 or 2, side take-off points.
  • the method for producing pure or enriched neral to be carried out preferably within the context of the method according to the invention is carried out at an absolute operating pressure in the dividing wall column or in the interconnection of two distillation columns in the form of a thermal coupling of from 5 to 200 mbar, preferably from 5 to 100 mbar, particularly preferably from 5 to 70 mbar and very particularly preferably from 10 to 50 mbar and especially preferably from 10 to 40 mbar.
  • the dividing wall column or the interconnection of two distillation columns in the form of a thermal coupling is operated here such that the absolute top pressure is 10 to 50 mbar, preferably 10 to 40 mbar.
  • the dividing wall column or the interconnection of two distillation columns in the form of a thermal coupling is operated here such that the absolute bottom pressure is 5 to 200 mbar, preferably 10 to 100 and particularly preferably 20 to 50 mbar.
  • the reflux ratio can be varied within wide limits and is usually about 5 : 1 to about 2000 : 1, preferably about 20 : 1 to 1000 : 1. Also advantageous is a dephlegmator procedure, i.e. only the return stream is condensed in the top condenser of the column and fed back to the column. In such an energetically favorable case of partial condensation, the top product to be discharged is produced exclusively in the aftercooler, which can be operated at a lower temperature.
  • neral in enriched form is to be understood as meaning neral-containing substance mixtures which have a higher content of neral than the neral/geranial comprising substance mixture used in step 0). For instance, such enrichment may be increasing the content of neral by at least 10 % by weight, by at least 25 % by weight, by at least 50 % by weight, by at least 75 % by weight, or by at least 85 % by weight, in comparison to the neral/geranial comprising substance mixture used in step 0).
  • the term neral in enriched form (or equivalent terms such as pure or enriched neral or similar terms) is to be understood as meaning neral which has a purity, i.e.
  • a neral content of from 80 to 95% by weight, preferably from 85 to 95% by weight and very particularly preferably from 90 to 95% by weight based on the total amount of the respective substance mixtures.
  • the method according to the invention also permits the production of neral (cis-citral) in pure form.
  • neral in pure form is to be understood as meaning neral with a content greater than or equal to 95, 96 or 97% by weight, preferably greater than or equal to 98% by weight and particularly preferably 98 to 99.5% by weight based on the total amount of the respective substance mixtures.
  • the term “neral in pure form” is to be understood as meaning neral which has a geranial content of up to 1% by weight, preferably of from 0.05 to 0.5% by weight and particularly preferably from 0.1 to 0.3% by weight.
  • the neral in pure form accessible according to the invention has a content of isocitrals, such as, for example, isocitrals of the formulae (IV), (V) and (VI)
  • the term “geranial in enriched form” (or equivalent terms such as pure or enriched geranial or similar terms) is to be understood as meaning geranial-containing substance mixtures which have a higher content of geranial than the neral/geranial comprising substance mixture used in step 0). For instance, such enrichment may be increasing the content of geranial by at least 10 % by weight, by at least 25 % by weight, by at least 50 % by weight, by at least 75 % by weight, or by at least 85 % by weight, in comparison to the neral/geranial comprising substance mixture used in step 0).
  • the term geranial in enriched form is to be understood as meaning geranial which has a purity, i.e.
  • a geranial content of from 80 to 95% by weight, preferably from 85 to 95% by weight and very particularly preferably from 90 to 95% by weight based on the total amount of the respective substance mixtures.
  • the method according to the invention also permits the production of geranial (trans-citral) in pure form.
  • the term “geranial in pure form” is to be understood as meaning geranial with a content greater than or equal to 95, 96 or 97% by weight, preferably greater than or equal to 98% by weight and particularly preferably 98 to 99.5% by weight based on the total amount of the respective substance mixtures.
  • the term “neral in pure form” is to be understood as meaning neral which has a geranial content of up to 1% by weight, preferably of from 0.05 to 0.5% by weight and particularly preferably from 0.1 to 0.3% by weight.
  • the geranial in pure form accessible according to the invention has a content of isocitrals, such as, for example, isocitrals of the formulae (IV), (V) and (VI) of up to 2% by weight, preferably of from 0.1 to 1% by weight, where all of the data within the context of the present invention refer to the total amount of the respective substance mixtures.
  • an educt mixture (comprising neral and geranial e.g., a neral/geranial comprising substance mixture used in step 0)) having a first mass ratio of neral : geranial is subjected to irradiation with light in step a) and wherein, after irradiation, a product mixture is obtained that has a second mass ratio of neral : geranial that differs from the first mass ratio of neral : geranial.
  • the first mass ratio of neral : geranial and the second first mass ratio of neral : geranial differ from one another by at least 5%, by at least 10%, by at least 20%, by at least 30%, by at least 50%, or by at least 75%.
  • the feed i.e. the substance mixture to be used
  • the neral product of value is produced in the desired purity.
  • a postcondenser is connected downstream of the top condenser of the column and is cooled with cooling liquid (for example sols), and a low-neral low-boiling fraction is also produced therein.
  • the feed mixture is fractionated into two fractions, a low-boiling top fraction and a high-boiling bottom fraction.
  • a low-boiling top fraction When separating feed mixtures into more than two fractions, it is necessary to use a plurality of distillation columns according to this process variant.
  • columns with liquid or vaporous side take-offs are used if possible in the separation of multisubstance mixtures.
  • Dividing wall columns are described, for example, in US 2,471 ,134; US 4,230,533; EP 0 122 367; EP 0 126288; EP 0 133 510; Chem. Eng. Technol. 10 (1987) 92 - 98; Chem.-lng.- Tech. 61 (1989) No.1 , 16 - 25; Gas Separation and Purification 4 (1990) 109 - 114; Process Engineering 2 (1993) 33 - 34; Trans IChemE 72 (1994) Part A 639 - 644 and Chemical Engineering 7 (1997) 72 - 76.
  • the method of the present invention comprises a) the isomerization of neral, especially of enriched or pure neral to a mixture of neral and geranial by irradiation with light, or a) the isomerization of geranial, especially of enriched or pure geranial to a mixture of neral and geranial by irradiation with light.
  • a solution of geranial, or neral in a solvent is irradiated with light.
  • the solvent is preferably selected from water, dichloromethane, trichloromethane, tetrachloromethane, CS2, Ci- C4alcohols, chlorobenzene, fluorobenzene, trifluoromethylbenzene, acetonitrile, dimethylformamide (DMF), dimethylsulfoxide (DMSO), tetrahydrofuran (THF), ethylacetate, acetone and mixtures thereof.
  • DMF dimethylformamide
  • DMSO dimethylsulfoxide
  • THF tetrahydrofuran
  • step a) i.e. geranial, and/or neral in neat form are irradiated with light, in particular monochromatic light.
  • step a) the geranial in neat form is irradiated with light, in particular monochromatic light, or the method according to any of claims 1 , 4 and 5, wherein in step a) the neral in neat form is irradiated with light, in particular monochromatic light, or the method according to any of claims 1 to 5, wherein in step a) a mixture comprising or consisting of geranial and neral in neat form is irradiated with light, in particular monochromatic light.
  • Geranial and/or neral may be irradiated with light in the presence of a sensitizer.
  • a “(photo)sensitizer” in terms of the present invention is an organic molecule (generally a dye), or transition metal complex which, when subjected to irradiation (generally to electromagnetic radiation in the UV, in the visible or in the near IR region) is subject to “Dexter excitation transfer” (electron exchange excitation transfer): Excitation transfer occurring as a result of an electron exchange mechanism. It requires an overlap of the wavefunctions of the energy donor (sensitizer) and the energy acceptor (neral/geranial). It is the dominant mechanism in triplet-triplet energy transfer.
  • the sensitizer is preferably selected from [lr(dF(CF 3 )ppy)2(bpy)]PFe, (lr[dF(CF 3 )ppy] 2 (dtbbpy))PF 6 , (lr[dF(CF 3 )ppy] 2 (dtbpy))PF 6 , (lr[dF(Me)ppy] 2 (dtbbpy))PF 6 , [lr(dtbbpy)(ppy)2]PFe, lr(ppy) 3 , Ru(bpy) 3 CI 3 , [Ru(bpy) 3 ](PFe)2, benzophenone, thioxanthen-9- one, Michler's Ketone, tetramethoxy-antracen-9-one, diacetyl-4,5-bis(carbazol-9-yl)-1 ,2- dicyanobenzene (2CzPN), 3,4,5,6-tetra(9H-carbazol-9-y
  • the irradiation is done with light in the wavelength range of 300 to 800 nm, in particular in the absorption range of the sensitizer, usually in the wavelength range of 350 to 490 nm.
  • the light source for use in performing light irradiation are, although not limited to, high-pressure mercury lamps, xenon lamps, fluorescent lamps, incandescent lamps, electroluminescent lighting devices etc.
  • the term “light” in the proper sense is electromagnetic radiation with a wavelength (range) in the visible spectrum (380 to 780 nm).
  • the term “light” also encompasses the directly adjacent wavelength spectrum, i.e. near IR (>780 nm to 1 pm) and near UV (300 to ⁇ 380 nm).
  • irradiation comprises or consists of irradiation with light of a wavelength in the range of between 300 and 1000 nm, of between 300 and 490 nm, of between 300 and 420 nm, of between 350 and 490 nm, of between 350 and 370 nm, of between 400 and 410 nm.
  • irradiation comprises or consists of irradiation with light of a wavelength of (approximately) 365 nm, or of (approximately) 405 nm.
  • step a) the geranial is irradiated with monochromatic light.
  • step a) the neral is irradiated with monochromatic light.
  • Such monochromatic light may also be light within the abovereferenced preferred wavelength ranges.
  • Monochromatic light consists of a (small) bandwidth of wavelengths. It will be understood that monochromatic light may be understood in the broadest sense as generally understood in the art. For instance, monochromatic light may exhibit a halfwidth of 0 to 50 nm, of +/- 0.1 to +/- 40 nm, of +/- 0.5 to +/- 30 nm, or of +/- 10 to +/- 30 nm, in relation to the wavelength of the emission maximum.
  • monochromatic light preferably exhibits light with a full width at half maximum (FWHM) (which may optionally be considered as halfwidth) of not more than 150 nm, preferably not more than 100 nm, more preferably not more than 75 nm, even more preferably not more than 60 nm, in particular not more than 50 nm, or nor more than 30 nm or nor more than 25 nm, or not more than 10 nm.
  • FWHM full width at half maximum
  • At least 80%, more preferably at least 90%, in particular at least 99% of the applied light intensity may be the designated light.
  • a filter isolates monochromatic light from a broadband light source; lasers or LEDs generate monochromatic light directly.
  • the irradiation is preferably done with monochromatic light in the wavelength range of 300 to 800 nm, in particular in the absorption range of the sensitizer, usually in the wavelength range of 350 to 490 nm.
  • step (a) the reaction mixture, which consists of neral, or geranial and sensitizer and optionally solvent, is irradiated with light in the wavelength range of from 300 to 800 nm.
  • step (a) the reaction mixture consists of neral, or geranial and sensitizer and solvent.
  • step (a) the reaction mixture consists of neral, or geranial and sensitizer.
  • step (a) the reaction mixture is irradiated with light in the wavelength range of from 350 to 490 nm.
  • step (a) the reaction mixture is irradiated with monochromatic light.
  • step (a) where irradiation in step (a) is carried out using a filter which provides monochromatic light from a broadband light source, wherein at least 90% of the monochromatic light is in the wavelength range of from 300 to 800 nm, preferably a monochromatic light source, more preferably an electroluminescent lighting device emitting monochromatic light, where at least 90% of the light emitted by said monochromatic light source is in the wavelength range of from 300 to 800 nm.
  • a filter which provides monochromatic light from a broadband light source, wherein at least 90% of the monochromatic light is in the wavelength range of from 300 to 800 nm, preferably a monochromatic light source, more preferably an electroluminescent lighting device emitting monochromatic light, where at least 90% of the light emitted by said monochromatic light source is in the wavelength range of from 300 to 800 nm.
  • step (a) is carried out using a monochromatic light source, preferably an electroluminescent lighting device emitting monochromatic light, where at least 90% of the light emitted by said monochromatic light source is in the wavelength range of from 350 to 490 nm.
  • a monochromatic light source preferably an electroluminescent lighting device emitting monochromatic light, where at least 90% of the light emitted by said monochromatic light source is in the wavelength range of from 350 to 490 nm.
  • step (a) The method according to any of embodiments E.6, or E.7, where irradiation in step (a) is carried out using an electroluminescent lighting device emitting monochromatic light, where the electroluminescent lighting device consists of at least one LED.
  • the amount of photosensitizer used in the reaction is at a concentration that ensures absorbance of light in the photoreactor in the range of 0.1 to 3.0, preferably in the range of 0.5 to 2.5, and most preferably in the range of 1.0 to 2.0.
  • “Absorbance” is defined as the logarithm of the ratio of incident to transmitted radiant power through a sample (excluding the effects on cell walls).
  • monochromatic light as understood within this disclosure is preferably all radiation at least 90 % of its power and at most 100 % thereof being emitted in the range from 350 nm to 490 nm.
  • the power of minor components of the monochromatic light being outside the given wavelength at most amounts up to 10 % depending on the filter-free electroluminescent lighting device employed, the nature and quantity of the photosensitizer and the organic solvent.
  • the great majority of embodiments of monochromatic light only contains small amounts of light portions beyond 350 nm to 490 nm.
  • monochromatic light is understood to be an entity, at least 95 % of the power of said monochromatic light and at most 100 % of said power being emitted in the range from 350 nm to 490 nm.
  • monochromatic light means, at least 98 % and further preferred at least 99 % of the power of said monochromatic light and at most 100 % of said power being emitted in the range from 350 nm to 490 nm.
  • the amount of the monochromatic light is expressed in power since by doing so one is not urged to otherwise define the permissible amount of light in lumen Im or Wh or candela cd above and below the claimed wavelength range. Said amount, when not expressed in power, would vary as a function of the wavelength considered.
  • monochromatic light is all radiation at least 90 % of its power and at most 100 % thereof being emitted in the range from 350 nm to 490 nm and its monomodal emission spectrum preferably exhibiting a halfwidth of not more than +/- 100 nm, preferably not more than +/- 60 nm, such as +/- 10 to +/- 30 nm, in relation to the wavelength of the emission maximum. Said defined halfwidth gives a highly structured lighting signal, which results in an improved yield of neral/geranial.
  • step a no sensitizer is present in step a).
  • the irradiation is preferably done with monochromatic light in the wavelength range of 300 to 800 nm, in particular in the wavelength range of 300 to 420 nm.
  • step (a) the reaction mixture, consisting of neral, or geranial and optionally solvent, is irradiated with light in the wavelength range of from 300 to 800 nm.
  • step (a) The method according to embodiment F.1 , where in step (a) the reaction mixture consists of neral, or geranial and solvent.
  • step (a) The method according to embodiment F.1 , or F.2, where in step (a) the reaction mixture consists of neral, or geranial.
  • step (a) The method according to any of embodiments F.1 to F.3, where in step (a) the reaction mixture is irradiated with light in the wavelength range of from 300 to 420 nm.
  • step (a) the reaction mixture is irradiated with monochromatic light.
  • step (a) The method according to embodiment F.5, where irradiation in step (a) is carried out using a filter which provides monochromatic light from a broadband light source, wherein at least 90% of the monochromatic light is in the wavelength range of from 300 to 800 nm, preferably a monochromatic light source, more preferably an electroluminescent lighting device emitting monochromatic light, where at least 90% of the light emitted by said monochromatic light source is in the wavelength range of from 300 to 800 nm.
  • a filter which provides monochromatic light from a broadband light source, wherein at least 90% of the monochromatic light is in the wavelength range of from 300 to 800 nm, preferably a monochromatic light source, more preferably an electroluminescent lighting device emitting monochromatic light, where at least 90% of the light emitted by said monochromatic light source is in the wavelength range of from 300 to 800 nm.
  • step (a) The method according to embodiment F.6, where irradiation in step (a) is carried out using a monochromatic light source, preferably an electroluminescent lighting device emitting monochromatic light, where at least 90% of the light emitted by said monochromatic light source is in the wavelength range of from 300 to 420 nm.
  • a monochromatic light source preferably an electroluminescent lighting device emitting monochromatic light, where at least 90% of the light emitted by said monochromatic light source is in the wavelength range of from 300 to 420 nm.
  • step (a) The method according to embodiments F.6, or F.7, where irradiation in step (a) is carried out using an electroluminescent lighting device emitting monochromatic light, where the electroluminescent lighting device consists of at least one LED.
  • step a) the geranial is irradiated with light, in particular monochromatic light, in the wavelength range of 300 to 420 nm; or in step a) the neral is irradiated with light, in particular monochromatic light, in the wavelength range of 300 to 420 nm; in step a) a mixture comprising or consisting of geranial and neral in neat form is irradiated with light, in particular monochromatic light, wherein preferably at least 90 % and at most 100 % of the radiant flux of the light, in particular monochromatic light, is emitted in the range from 300 nm to 420 nm and its monomodal emission spectrum preferably exhibiting a halfwidth of not more than +/- 100 nm, preferably not more than +/- 60 nm, such as +/- 10 to +/- 30 nm, in relation to the wavelength of the emission maximum, and/or wherein preferably the geranial in neat form, the
  • monochromatic light as understood within this disclosure is preferably all radiation at least 90 % of its power and at most 100 % thereof being emitted in the range from 300 nm to 420 nm.
  • the power of minor components of the monochromatic light being outside the given wavelength at most amounts up to 10 % depending on the filter-free electroluminescent lighting device employed, the nature and quantity of the organic solvent.
  • the great majority of embodiments of monochromatic light only contains small amounts of light portions beyond 300 nm to 420 nm.
  • monochromatic light is understood to be an entity, at least 95 % of the power of said monochromatic light and at most 100 % of said power being emitted in the range from 300 nm to 420 nm.
  • monochromatic light means, at least 98 % and further preferred at least 99 % of the power of said monochromatic light and at most 100 % of said power being emitted in the range from 300 nm to 420 nm.
  • the amount of the monochromatic light is expressed in power since by doing so one is not urged to otherwise define the permissible amount of light in lumen Im or Wh or candela cd above and below the claimed wavelength range. Said amount, when not expressed in power, would vary as a function of the wavelength considered.
  • monochromatic light is all radiation at least 90 % of its power and at most 100 % thereof being emitted in the range from 300 nm to 420 nm and its monomodal emission spectrum preferably exhibiting a halfwidth of not more than +/- 100 nm, preferably not more than +/- 60 nm, such as +/- 10 to +/- 30 nm, in relation to the wavelength of the emission maximum. Said defined halfwidth gives a highly structured lighting signal, which results in an improved yield of neral/geranial.
  • the irradiation with light is preferably accomplished by the use of a LED (light emitting diode), or laser.
  • LED used in this context can also refer to organic light emitting diodes (OLEDs), an active matrix organic light emitting diode (AMOLED), or any other diode based lighting source.
  • OLEDs organic light emitting diodes
  • AMOLED active matrix organic light emitting diode
  • the LED refers to a high-power LED that can be used with 350 mW electrical power or more.
  • the LED is configured to be applied with an electrical power above 1 W.
  • the light emitted by the LED unit is chosen such that at least a part of the light can be used in the isomerisation.
  • the LED unit is adapted to emit light in the ultraviolet and (optionally) visible part of the electromagnetic spectrum, preferably light with a wavelength between 300 and 800 nm, more preferably between 300 and 420 nm, or 350 and 490 nm.
  • a filter-free electroluminescent lighting device within this disclosure is any electroluminescent device emitting light, which does not comprise a filtering means.
  • a filtering means can be a layer, a chemical compound or product applied onto the lighting device.
  • a filtering means can also be a compound, which is immersed or solubilized in a solvent circulating, pumped or floating around the lighting device and adapted to absorb light in a distinct range but not to transfer energy emerging from said absorbed light onto neral/geranial.
  • the electroluminescent lighting device is required not to operate by means of any kind of chemically induced lighting like gas ionization or by means of heating.
  • the filter-free electroluminescent lighting device is understood to provide light (photons) emerging from electrons supplementing holes or gaps in an electron-poor material with emission of electromagnetic radiation preferably in the form of visible light.
  • Said filter-free electroluminescent lighting device is selected from the group of light emitting electrochemical cells, electroluminescent wires, field-induced electroluminescent polymers, light emitting diodes, organic light emitting diodes, polymer light emitting diodes, active-matrix organic light-emitting diodes (AMOLED’s), electroluminescent films especially based on inorganic luminescent materials,- semiconductor lasers, diode lasers.
  • the electroluminescent lighting device include chemical lasers, dye lasers, free-electron lasers, gas dynamic lasers, gas lasers, ion lasers, laser flashlights, metal-vapor lasers, non-linear optics quantum well lasers, ruby lasers, solid-state lasers etc.
  • step a) the geranial is irradiated with light, in particular monochromatic light, in the wavelength range of 350 to 490 nm; or in step a) the neral is irradiated with light, in particular monochromatic light, in the wavelength range of 350 to 490 nm, wherein preferably at least 90 % and at most 100 % of the radiant flux of the light, in particular monochromatic light, is emitted in the range from 350 nm to 490 nm and its monomodal emission spectrum preferably exhibiting a halfwidth of not more than +/- 100 nm, preferably not more than +/- 60 nm, such as +/- 10 to +/- 30 nm, in relation to the wavelength of the emission maximum, and /or wherein preferably the geranial and/or neral is irradiated in the presence of a sensitizer.
  • Working at this somewhat smaller wavelength range still provides good conversion rates into and high yields of neral/geranial, however, by means of a narrower wavelength spectrum thus expending less power and energy.
  • Side reactions like e.g. isomerization into undesired compounds are even further suppressed or preferably completely avoided at this wavelength range.
  • Narrowing of the wavelength range within the filter-free, electroluminescent lighting device is achieved by selectively controlling distinct electronic parts within said device.
  • the irradiation may be carried out in a continuously stirred reaction vessel, in a pumping circuit, or in a continuous flow reactor.
  • the lighting device and photochemical reactor described in WO2021/233951 and/or W02023/011951A1 may be used in conducting step a) of the process of the present invention.
  • Step a) is preferably done in a temperature range of -20 to 100 ° C.
  • the method according to the invention comprises, as step b) the separation of the mixture comprising geranial and neral obtained in step a) to give enriched or pure geranial and enriched or pure neral, especially by way of distillation, or chromatographic separation processes.
  • the method according to the invention comprises, as step b) the (continuous) distillative separation of the mixture comprising geranial and neral obtained in step a) to give enriched or pure geranial and enriched or pure neral.
  • step b) the same preferences apply as for step 0).
  • step b) involves also the distillative removal of solvent and the separation of the sensitizer, which remains as residue in the distillation, and optionally its reuse in step a).
  • the distillative separating is a continuous method for isolating geranial in pure or enriched form by distillative removal of geranial from substance mixtures comprising neral and geranial, the distillative removal being carried out in a dividing wall column or in an interconnection of two distillation columns in the form of a thermal coupling having 80 to 200 theoretical plates and one or more side take-off points at an absolute operating pressure, i.e. at an absolute pressure in the dividing wall column or the interconnection of two distillation columns in the form of a thermal coupling of from 5 to 200 mbar.
  • the distillative separating is preferably a continuous method for isolating neral in pure or enriched form by distillative removal of neral from substance mixtures comprising neral and geranial, the distillative removal being carried out in a dividing wall column or in an interconnection of two distillation columns in the form of a thermal coupling having 80 to 200 theoretical plates and one or more side take-off points at an absolute operating pressure, i.e. at an absolute pressure in the dividing wall column or the interconnection of two distillation columns in the form of a thermal coupling of from 5 to 200 mbar.
  • the dividing wall column has 80 to 200, preferably 100 to 180, theoretical plates and one or more, preferably 1 to 3, particularly preferably 1 or 2, side take-off points.
  • Step b) is carried out at an absolute operating pressure in the dividing wall column or in the interconnection of two distillation columns in the form of a thermal coupling of from 5 to 200 mbar, preferably from 5 to 100 mbar, particularly preferably from 5 to 70 mbar and very particularly preferably from 10 to 50 mbar and especially preferably from 10 to 40 mbar.
  • the dividing wall column or the interconnection of two distillation columns in the form of a thermal coupling is operated here such that the absolute top pressure is 10 to 50 mbar, preferably 10 to 40 mbar.
  • the dividing wall column or the interconnection of two distillation columns in the form of a thermal coupling is operated here such that the absolute bottom pressure is 5 to 200 mbar, preferably 10 to 100 and particularly preferably 20 to 50 mbar.
  • the reflux ratio can be varied within wide limits and is usually about 5 : 1 to about 2000 : 1, preferably about 20 : 1 to 1000 : 1. Also advantageous is a dephlegmator procedure, i.e. only the return stream is condensed in the top condenser of the column and fed back to the column. In such an energetically favorable case of partial condensation, the top product to be discharged is produced exclusively in the aftercooler, which can be operated at a lower temperature.
  • the feed i.e. the substance mixture to be used
  • the feed can be fed in liquid or gaseous form into the dividing wall column or the interconnection of two distillation columns in the form of a thermal coupling, preferably into the dividing wall column, and be separated there into a top and bottom fraction and also one or more, preferably into two or more, side take-offs as described above.
  • the neral product of value (or the geranial product of value) is produced in the desired purity.
  • the present invention is directed to a method for the preparation of enriched or pure neral.
  • the present invention is directed to a method for the preparation of enriched or pure geranial.
  • Step 0) includes the distillative separation of mixtures comprising geranial and neral to give enriched or pure geranial and neral.
  • a substance mixture which is used in step 0) consists preferably of 30 to 70% by weight, preferably of 40 to 60% by weight, of neral, of 70 to 30% by weight, preferably of 60 to 40% by weight, of geranial and of 0 to 5% by weight of further components, where the percentages add up to 100% by weight.
  • step a) the enriched or pure geranial obtained in step 0) is isomerized to a mixture of neral and geranial by irradiation with light.
  • the enriched or pure geranial in neat form is irradiated with light, i.e. no solvent and photosensitizer are present.
  • the enriched or pure geranial is isomerized to the (photo)equilibrium between neral and geranial by irradiation with light.
  • the isomerization of neral, or geranial by irradiation with light does not lead to the thermodynamic equilibrium between neral and geranial (ca. 40 % neral/ca.
  • Step a) is preferably done in a temperature range of -20 to 100 ° C.
  • Step a) is preferably done in a pressure range from 1 mbar to 20 bar.
  • Step b) involves the distillative separation of the mixture comprising geranial and neral obtained in step a) to give enriched or pure geranial and neral.
  • the product neral is collected.
  • step b) The (undesired) enriched or pure geranial obtained in step b) is recycled according to step c) in step a), i.e. isomerized to the (photo)equilibrium between neral and geranial by irradiation with light.
  • step a) The recycling of the (undesired) enriched or pure geranial obtained in step b) to step a) allows for improved yields of enriched or pure neral to be achieved in the process of the invention.
  • the mass ratio of neral : geranial of an educt such as, e.g., a mixture comprising neral and geranial, may be altered by means of conducting a method of the present invention.
  • an obtainable (or obtained) product may bear special characteristics.
  • a further aspect of the present invention thus relates to a mixture comprising neral and geranial obtainable (or obtained) from a method of the present invention.
  • the mixture has a mass ratio of neral : geranial of >1.25 or ⁇ 0.75, in particular of >1.5. In a preferred embodiment, the mixture has a mass ratio of neral : geranial of >1.75 or >2.0 or >3.0. This may be achieved by isomerization of step a) optionally in combination with enriching neral. In an alternative preferred embodiment, the mixture has a mass ratio of neral : geranial of ⁇ 0.7 or >0.6 or >0.5. This may be achieved by isomerization of step a) optionally in combination with enriching geranial.
  • the mixture has a mass ratio of neral : geranial between 1 : 1.25 to 1.25 : 1.
  • the neral, or geranial obtained according to the method of the present invention are useful intermediates in the production of, for example, menthol, or linalool.
  • the neral, or geranial, especially neral obtained according to the method of the present invention may be used for producing menthol, especially optically active menthol.
  • the method according to the present invention may comprise
  • Step d.1) Catalytic hydrogenation of neral and/or geranial to give citronellal
  • stage d.1 of the method for producing menthol a catalytic hydrogenation of neral is carried out to give citronellal, preferably a catalytic hydrogenation of neral produced as described above.
  • Hydrogenation of citral a wide-spread model reaction for selective reduction of a,p-unsaturated aldehydes.
  • the catalytic activity of the optically active transition metal catalysts used for the homogeneous-catalytic asymmetric hydrogenation of geranial/neral, which comprise rhodium as catalytically active transition metal can be significantly increased by adding a phosphine compound, such as, for example,
  • the racemic or optically active citronellal accessible in this way is usually produced in high yield and in particular high chemical and optical purity.
  • D-citronellal preferably D-citronellal
  • it can be further purified by separation and/or purification methods known per se to the person skilled in the art.
  • a prepurification of the citronellal-containing product mixture obtained by the presented hydrogenation by means of a falling film evaporator and subsequent fine distillation of the citronellal has proven to be advantageous.
  • a further aspect of the invention is directed to a process for the preparation of citronellal, preferably optically active citronellal, comprising the steps of d.0) optionally separating the citral having a neral : geranial mass ratio as obtainable (or obtained) according to the invention, preferably having a neral : geranial mass ratio of >1 , preferably >1.5, into geranial and neral; and d.1) preparation of optically active citronellal by asymmetric hydrogenation of the citral of the step d.0) or of citral having a neral : geranial mass ratio as obtainable (or obtained) according to the invention, preferably having a neral : geranial mass ratio of >1, preferably >1.5.
  • a further aspect of the present invention relates to citronellol, which may be optionally optically active cintronellol, obtainable (or obtained) from a method of the present invention.
  • Isopulegol (5-methyl-2-(1-methylethenyl)-cyclohexanol) may have three asymmetric carbon atoms and therefore four stereoisomers, each occurring as a pair of enantiomers.
  • a further aspect of the invention is directed to a process for the preparation of isopulegol, preferably optically active isopulegol, preferably L-isopulegol, comprising the steps of (d.0) optionally separating the citral having a neral : geranial mass ratio as obtainable (or obtained) according to the invention, preferably having a neral : geranial mass ratio of >1, preferably >1.5, into geranial and neral; d.1) preparation of optically active citronellal by asymmetric hydrogenation of the citral of the step d.0) or of citral having a neral : geranial mass ratio as obtainable (or obtained) according to the invention, preferably having a neral : geranial mass ratio of >1, preferably >1.5; and e.1) cyclization of the citronellal of step d.1) to give isopulegol in the presence of a suitable acid, preferably a Lewis acid.
  • a further aspect of the present invention relates to isopulegol, which may be optionally optically active isopulegol, preferably L-isopulegol, obtainable (or obtained) from a method of the present invention.
  • a further aspect of the invention is directed to a process for preparation of menthol, preferably L-menthol, comprising the steps of d.0) optionally separating the citral having a neral : geranial mass ratio as obtainable (or obtained) according to the invention, preferably having a neral : geranial mass ratio of >1, preferably >1.5, into geranial and neral; d.1) preparation of optically active citronellal by asymmetric hydrogenation of the citral of the step d.0) or of citral having a neral : geranial mass ratio as obtainable (or obtained) according to the invention, preferably having a neral : geranial mass ratio of >1, preferably >1.5; e.1) cyclization of the citronellal of step d.1) to give isopulegol in the presence of a suitable catalyst; f.1.) optionally purification of isopulegol such as, e.g., by crystallization;
  • a further aspect of the present invention is directed to a process for the preparation of optically active menthol using neral and/or geranial, in particular pure neral or a mixture of neral and geranial that comprises a neral : geranial mass ratio of >1, preferably >1.5, obtained by the process according to the invention.
  • a further aspect of the invention is directed to a process for the preparation of optically active menthol, preferably L-menthol, comprising the steps of optionally separating the citral having a neral : geranial mass ratio as obtainable (or obtained) according to the invention, into geranial and neral; preparation of optically active citronellal by asymmetric hydrogenation of the citral; cyclization of the optically active citronellal prepared in this way to give optically active isopulegol in the presence of a suitable acid, preferably a Lewis acid, and hydrogenation of the optically active isopulegol prepared in this way to give optically active menthol.
  • a suitable acid preferably a Lewis acid
  • a further aspect of the present invention relates to menthol, which may be optionally optically active menthol, in particular L-menthol, obtainable (or obtained) from a method of the present invention.
  • Step e.1 Cyclization of citronellal to give isopulegol
  • step e.1) of the method according to the invention a cyclization of citronellal which has been obtained by the above-described step d.1) by catalytic hydrogenation of neral, to give isopulegol is carried out in the presence of an acidic catalyst.
  • an acidic catalyst for example, W02006092433A1 and US7550633.
  • An overview of the available acidic or Lewis-acidic reagents or catalysts can be found, for example, under E. J. Lenardao, G. V. Botteselle, F. de Azambuja, G. Perin, R. G. Jacob Tetrahedron 2007, 63, 6671-6712.
  • customary catalysts and reagents such as for example: silica gel or aluminum oxide or mixtures thereof, as disclosed e.g. in W02004/089299, zeolites, as described e.g. for the case of boron-containing zeolites in W02004/101480.
  • Further customary acidic or Lewis-acidic catalysts are, for example, zinc bromide, as described e.g. in Synthesis 1978, 147-148 and in EP1053974A1 or else tungsten-containing acids as described in BR2005002489A.
  • EP1225163A describes the cyclization of citronellal to isopulegol in the presence of tris(2,6-diphenylphenol)aluminum catalysts.
  • Tris(2,6-diphenylphenol)aluminum is known in the literature and as catalyst for selective 1 ,4-functionalizations of a,p-unsaturated carbonyl compounds and for specific Claisen rearrangements, for example in Angew. Chem. Int. Ed. 2004, 43, 994.
  • the specified catalyst system is also suitable for use in the course of step e.1) of the method according to the invention.
  • W02007/039342 and W02007/039366 likewise disclose aluminum-containing homogeneous catalysts, specifically those which have one or more siloxide ligands on the aluminum.
  • the disclosed aluminum-siloxide compounds are suitable as catalysts for intramolecular Prins reactions, including the cyclization of citronellal to isopulegol.
  • the cyclization of citronellal to isopulegol may be achieved by cyclization in the presence of at least one Lewis-acidic aluminum-containing catalyst, such as a bis(diarylphenoxy)aluminum compound, which may be used in the presence of an auxiliary, such as a carboxylic anhydride.
  • the isopulegol may be recovered from the catalyst-containing reaction product by distillative separation to give an isopulegol-enriched top product and an isopulegol-depleted bottom product. From the bottom product, the at least one catalyst may be regenerated.
  • step f.1) of the method according to the invention a purification of isopulegol obtainable as described above according to step e.1) of the method according to the invention by crystallization is carried out.
  • W02007/023109 discloses a method for producing enriched isopulegol, specifically enriched L- isopulegol by crystallization from a melt comprising L-isopulegol.
  • Such a method for the purification of isopulegol, specifically of optically active L-isopulegol by melt crystallization constitutes a preferred method for the purification of isopulegol by crystallization according to step f.1).
  • the isopulegol obtained by crystallization as described above according to step e.1) of the method according to the invention can also be further purified by further separating methods, preferably by distillation.
  • further separating methods preferably by distillation.
  • Step g.1 Catalytic hydrogenation of isopulegol to give menthol
  • step g.1) of the method according to the invention a catalytic hydrogenation of isopulegol obtained according to step f.1) to menthol is carried out.
  • the catalytic hydrogenation of racemic or optically active isopulegol according to step g.1) of the method according to the invention is carried out in the presence of a heterogeneous nickel-containing catalyst.
  • the catalytic hydrogenation according to step g.1) is preferably carried out in the presence of a heterogeneous nickel- and copper-containing catalyst.
  • Nickel, nickel/copper and cobalt catalysts are described as suitable catalysts. Specific nickel catalysts have also been used for the catalytic hydrogenation of piperitol to give menthol, as described in GB1 ,503,723.
  • EP1532091 discloses a method for producing racemic menthol by catalytic hydrogenation of isopulegol which has been used in the form of a diastereomer mixture of 70.1% isopulegol, 18.1% neo-isopulegol, 6.8% iso-isopulegol and 2.6% neoiso-isopulegol.
  • the catalyst used was Raney nickel doped with iron and chromium. This gave menthol in the form of a mixture of the possible diastereomers which consisted to 61.4% of menthol and to 35.6% of the further diastereomers of menthol.
  • a further route to menthol is that of processes for the diastereoselective cyclization of citronellal to isopulegol, as described, for example, in the aforementioned EP1225163 or W02006/092433.
  • the isopulegol obtained in this way can then be hydrogenated to menthol in a further step.
  • EP1053974 discloses a method for the catalytic hydrogenation of isopulegol to menthol in the presence of a catalyst of 5% palladium on carbon at a hydrogen pressure of 5 bar.
  • EP0394842 relates to catalysts for the hydrogenation of aliphatic unsaturated compounds, which comprises nickel and copper and is characterized by a content of from 20 to 75% by weight of nickel oxide, 10 to 75% by weight of zirconium dioxide and 5 to 50% by weight of copper oxide, in each case based on the oxidic, unreduced catalyst.
  • substrate specified are: butyne-2-diol-1 ,4, butene-2-diol-1 ,4 and 2-ethylhexen-2-al.
  • a method for producing racemic or optically active menthol ( ) is carried out by catalytic hydrogenation of racemic or optically active isopulegol the presence of hydrogen and a catalyst comprising
  • a catalyst that is particularly preferred for use in the course of step g.1) of the method according to the invention consists to 49 to 53% by weight of NiO, to 15 to 19% by weight of CuO, to 28 to 32% by weight of ZrO 2 and to 1 to 2% by weight of MoOa, and optionally to 0 to 3% by weight of further components, such as, for example, graphite, the fractions by weight of the individual components selected in each case adding up to 100% by weight.
  • Catalysts of this type are known and can be produced, for example, as described in EP0696572, to which reference is made in this regard in its entirety.
  • the catalysts in the course of step g.1) can be produced, for example, as described on pages 65 to 67 of W02009/068444. h.1) Fine distillation of menthol
  • the method according to the invention therefore comprises, in the context of a preferred embodiment as further optional step h.1 ), the distil lative purification of racemic and/or optically active menthol preferably by means of a dividing wall column.
  • the present invention also relates to a method for producing optically active menthol, comprising the steps d.2) asymmetric catalytic hydrogenation of neral and/or geranial to give optically active citronellal, e.2) cyclization of optically active citronellal obtained according to step d.2) to give optically active isopulegol in the presence of an acidic catalyst, f.2) purification of optically active isopulegol obtained according to step e.2), preferably by crystallization and g.2) catalytic hydrogenation of optically active isopulegol obtained according to any of steps e.2) or f.2) to give optically active menthol.
  • an asymmetric hydrogenation of neral is carried out.
  • an asymmetric catalytic hydrogenation, as described above under step d), of pure or enriched neral is carried out.
  • optically active citronellal is accessible, if desired, depending on the configuration of the asymmetric catalytic hydrogenation, in the form of one of the two enantiomers, preferably in the form of D-citronellal.
  • optically active citronellal obtainable according to step d.2) can then be cyclized according to step e.2) to give optically active isopulegol in the presence of an acidic catalyst.
  • Suitable acidic catalysts which may be mentioned are the acidic or Lewis-acidic catalysts described above in step d.1), such as the diarylphenoxyaluminum compounds.
  • optically active isopulegol obtainable in this way is, according to step f.2) within the context of this preferred embodiment, purified by crystallization. Preference is given to carrying out a crystallization from the melt as described under step f.1). Within the context of this preferred embodiment of the method according to the invention, purified L-isopulegol is obtained.
  • step g.2 the optically active isopulegol obtainable in this way is then catalytically hydrogenated to give optically active menthol.
  • the catalytic hydrogenation of isopulegol to menthol is known to the person skilled in the art and can be carried out using a wide variety of customary heterogeneous hydrogenation catalysts. It has proven to be advantageous to carry out the catalytic hydrogenation in the presence of the nickel-, copper-, zirconium- and molybdenum-containing catalysts described above under step g.1).
  • a particular advantage of the method according to the invention that should be emphasized is that it opens up the route to optically active, preferably practically enantiomerically and diastereomerically pure L-menthol. A higher content of neral in the asymmetric hydrogenation leads to a higher enantiomer excess of the optically active citronellal formed.
  • the neral, or geranial, especially geranial obtained according to the method of the present invention may be used for producing linalool.
  • a further embodiment of the present invention is directed to a method for producing linalool and comprises the additional steps d’) and e’): d’) catalytic hydrogenation of geranial and/or neral obtained by the method of the present invention, preferably of geranial obtained by the method of the present invention, in particular of geranial obtained in any of steps 0), a) and/or b) (e.g., 0) and/or b), or a) and/or b)), especially catalytic hydrogenation of geranial obtained in any of steps 0), a) and/or b) (e.g., 0) and/or b), or a) and/or b)) in the presence of a supported ruthenium, rhodium, osmium, iridium or platinum catalyst, preferably a ruthenium catalyst supported on carbon black; to obtain geraniol; and e’) isomerization of geraniol in
  • Linalool may be prepared from geranial via a process comprising catalytic hydrogenation of geranial to obtain geraniol and isomerization thereof to linalool.
  • the hydrogenation of geranial to obtain geraniol may be achieved by hydrogenation in the presence of a supported ruthenium, rhodium, osmium, iridium or platinum catalyst, preferably a ruthenium catalyst supported on carbon black, ruthenium/iron catalyst supported on carbon, comprising 0.1 to 10% by weight of ruthenium and 0.1 to 5% by weight of iron.
  • a supported ruthenium, rhodium, osmium, iridium or platinum catalyst preferably a ruthenium catalyst supported on carbon black, ruthenium/iron catalyst supported on carbon, comprising 0.1 to 10% by weight of ruthenium and 0.1 to 5% by weight of iron.
  • the crude mixture of geraniol can be separated by rectification (see DE10223974) or can be used without purification in the isomerization of geraniol to linalool.
  • the isomerization of geraniol to obtain linalool may be achieved by isomerization in the presence of a tungsten catalyst, especially a dioxotungsten (VI) complex, very especially a dioxotungsten(VI) complex of the general formula (III), wherein Li and L2 are independently of each other a ligand selected from the group consisting of the aminoalcohols, the aminophenols and mixtures thereof; and m and n are each 1 or 2. Further details regarding the isomerization of geraniol may be found in W003/048091 and WO03/047749.
  • Additional Catalysts which can be used in the isomerization, are, for example, described in CN105218312B and CN111087343B.
  • One aspect of the invention hence is for an improved process for the preparation of linalool.
  • the preparation of linalool may be done as described herein or by other methods known in the art.
  • a further aspect of the present invention relates to linalool obtainable (or obtained) from a method of the present invention.
  • a further aspect of the invention is directed to a process for the preparation of vitamin A or vitamin A acetate comprising the steps of
  • citral having a neral : geranial mass ratio as obtainable (or obtained) according to the invention preferably having a neral : geranial mass ratio of ⁇ 1 , preferably ⁇ 0.75, into pseudoionone,
  • a further aspect of the present invention relates to vitamin A obtainable (or obtained) from a method of the present invention.
  • the sensitizer (as indicated) is weighed into the borosilicate glass ampoule, which is then sealed.
  • the ampoule is evacuated via a cannula and filled with argon. This procedure is repeated several times.
  • the solution of geranial/neral in acetonitrile (as indicated (AON)) is added via a syringe.
  • the prepared ampoule is irradiated for the specified time, wavelength, and radiometric power at 20 °C.
  • the reaction mixture is then analyzed by gas chromatography with flame ionization detector. The values given are GC area percentages (without solvent).
  • Examples 1 to 5 show that the geranial content of the mixture can be changed from 96 a% to ca. 50 a% by photochemical isomerization. An excess of neral is obtained by extending the irradiation time. Reference is made to Example 13.
  • a% (peak) area%.
  • Examples 6 to 9 show that the neral content of the mixture can be changed from 99 a% to ca. 60 a% by photochemical isomerization.
  • Composition 99.0 % Neral and 0.24 % Geranial and 0.76 % side products (determined by GC).
  • Composition 3.5 % Neral and 96.2 % Geranial and 0.3 % side products (determined by GC).
  • a 150 ml reaction flask made of borosilicate is several times evacuated and filled with argon. It is charged with almost pure geranial (26.8 g, 169.3 mmol geranial and 6.1 mmol neral), and irradiated for 5h with 365 nm LEDs (radient flux 10 W) at 20 °C. From time-to-time samples are taken, and the reaction mixtures are measured by 1 H-NMR spectroscopy. The molar ratios of geranial and neral are provided in the following table.
  • Example 14 is repeated, except that the reaction mixture is analyzed by quantitative GC.
  • Examples 13 and 14 demonstrate that in a mixture of neral and geranial obtained by irradiation with light the amount of neral is higher than the amount of geranial. Said fact is advantageous for the production of neral.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)

Abstract

La présente invention concerne un procédé, comprenant l'isomérisation de neral de formule (II) en géranial de formule (I), ou l'isomérisation du géranial en neral, caractérisé en ce que (a) l'isomérisation est réalisée par irradiation avec de la lumière. Le procédé selon la présente invention permet de convertir un isomère indésirable, qui est un sous-produit inévitable généré pendant la production de neral et/ou de géranial, en un isomère souhaité de manière hautement efficace, ce qui permet d'améliorer considérablement les performances économiques du procédé de production de l'isomère souhaité (avec un rendement élevé en évitant une distillation intensive coûteuse et d'éventuels produits secondaires).
PCT/EP2024/068132 2023-07-07 2024-06-27 Photoisomérisation de géranial et de neral Pending WO2025011972A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
EP23184205.5 2023-07-07
EP23184205 2023-07-07

Publications (1)

Publication Number Publication Date
WO2025011972A1 true WO2025011972A1 (fr) 2025-01-16

Family

ID=87196412

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/EP2024/068132 Pending WO2025011972A1 (fr) 2023-07-07 2024-06-27 Photoisomérisation de géranial et de neral

Country Status (1)

Country Link
WO (1) WO2025011972A1 (fr)

Citations (40)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE577036C (de) 1923-01-12 1933-05-22 Howards & Sons Ltd Verfahren zur Herstellung von synthetischem Menthol
US2471134A (en) 1946-07-17 1949-05-24 Standard Oil Dev Co Fractionation apparatus
US3218361A (en) 1960-06-08 1965-11-16 Glidden Co Process for recovering specific isopulegols
GB1503723A (en) 1975-10-14 1978-03-15 Scm Corp Hydrogenation of cyclic unsaturated compounds
US4230533A (en) 1978-06-19 1980-10-28 Phillips Petroleum Company Fractionation method and apparatus
US4338170A (en) * 1979-06-14 1982-07-06 Nissan Chemical Industries, Ltd. Isomerization of β-γ-unsaturated alcohol or its ester
EP0122367A2 (fr) 1983-01-26 1984-10-24 BASF Aktiengesellschaft Colonne de distillation fractionnée
EP0126288A2 (fr) 1983-04-21 1984-11-28 BASF Aktiengesellschaft Procédé d'opération de réactions chimiques et séparation simultanée par distillation d'un mélange en plusieurs fractions au moyen d'une colonne de distillation
EP0133510A1 (fr) 1983-08-03 1985-02-27 BASF Aktiengesellschaft Procédé de séparation par distillation d'un mélange azéotropique
EP0394842A1 (fr) 1989-04-27 1990-10-31 BASF Aktiengesellschaft Catalyseur pour l'hydrogénation de composés aliphatiques insaturés
EP0696572A1 (fr) 1994-08-08 1996-02-14 Basf Aktiengesellschaft Procédé pour la préparation d'amines
US5663460A (en) 1994-07-29 1997-09-02 Takasago International Corporation Liquid l-n-menthol composition and process for preparing the same
EP0992477A1 (fr) 1998-10-07 2000-04-12 Basf Aktiengesellschaft Procédé de préparation de citral
EP1053974A1 (fr) 1999-05-17 2000-11-22 Quest International B.V. Réactions utilisant des acides de Lewis
EP1225163A2 (fr) 2001-01-18 2002-07-24 Takasago International Corporation Procédé de préparation d'isopulégol
EP1318128A2 (fr) 2001-12-07 2003-06-11 Basf Aktiengesellschaft Procédé pour l'hydrogénation de composés carbonyles oléfinquement insaturés
WO2003047749A1 (fr) 2001-12-07 2003-06-12 Basf Aktiengesellschaft Procede d'isomerisation d'alcools allyliques
WO2003048091A2 (fr) 2001-12-07 2003-06-12 Basf Aktiengesellschaft Procede d'isomerisation d'alcools allyliques
DE10223974A1 (de) 2002-05-29 2003-12-11 Basf Ag Isolierung stereoisomerer Isoprenoidalkohole durch Rektifikation
WO2004089299A2 (fr) 2003-04-02 2004-10-21 Advancis Pharmaceutical Corporation Antigenes et adjuvants a administration transdermique pulsatile
WO2004101480A1 (fr) 2003-05-13 2004-11-25 Basf Aktiengesellschaft Procédé pour produire des énols cycliques
EP1532091A1 (fr) 2002-08-22 2005-05-25 Symrise GmbH & Co. KG Procede pour la production de menthol
WO2006040096A1 (fr) 2004-10-11 2006-04-20 Basf Aktiengesellschaft Procede pour preparer des composes de carbonyle optiquement actifs
WO2006092433A1 (fr) 2005-03-03 2006-09-08 Basf Aktiengesellschaft Composes d'aluminium diarylphenoxy
WO2007023109A1 (fr) 2005-08-26 2007-03-01 Basf Se Procede pour preparer de l'isopulegol enrichi
WO2007039342A1 (fr) 2005-09-26 2007-04-12 Symrise Gmbh & Co. Kg Reaction de prins intramoleculaire et catalyseurs appropries
WO2009013192A1 (fr) 2007-07-23 2009-01-29 Basf Se Procédé pour obtenir du menthol par hydrogénation d'isopulégol
WO2009068444A2 (fr) 2007-11-30 2009-06-04 Basf Se Procédé de production de menthol racémique et optiquement actif
US7550633B2 (en) 2004-12-22 2009-06-23 Basf Se Method for the production of isopulegol
CN105218312A (zh) 2015-11-03 2016-01-06 山东新和成药业有限公司 一种烯丙基醇经异构化法连续制备芳樟醇的方法
RU2579122C1 (ru) 2015-03-25 2016-03-27 Федеральное государственное бюджетное учреждение науки Новосибирский институт органической химии им. Н.Н. Ворожцова Сибирского отделения Российской академии наук (НИОХ СО РАН) Способ получения гераниаля
WO2016097242A1 (fr) 2014-12-19 2016-06-23 Basf Se Procédé de préparation de composés carbonyle optiquement actifs
WO2017060243A1 (fr) 2015-10-05 2017-04-13 Basf Se Procédé pour produire des catalyseurs ruthénium/fer/support de carbone
CN107879914A (zh) 2017-11-24 2018-04-06 万华化学集团股份有限公司 一种高效精馏柠檬醛制备橙花醛的方法及用于该方法的催化剂
CN111087343A (zh) 2019-11-29 2020-05-01 万华化学集团股份有限公司 一种羟基吡啶配体及其制备方法和催化应用
CN112125782A (zh) 2020-09-27 2020-12-25 万华化学集团股份有限公司 一种氢化柠檬醛制备高纯度橙花醇和香叶醛的方法
CN112142583A (zh) 2020-10-26 2020-12-29 万华化学集团股份有限公司 一种香叶醛制备橙花醛的方法
WO2021233951A1 (fr) 2020-05-18 2021-11-25 Basf Se Dispositif d'éclairage pour fournir de la lumière à utiliser dans une réaction photochimique
WO2023011951A1 (fr) 2021-08-02 2023-02-09 Basf Se Appareil pour effectuer des réactions photochimiques
CN116474824A (zh) 2023-03-09 2023-07-25 福建森美达生物科技有限公司 一种催化剂、提高柠檬醛中香叶醛含量的方法和装置

Patent Citations (41)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE577036C (de) 1923-01-12 1933-05-22 Howards & Sons Ltd Verfahren zur Herstellung von synthetischem Menthol
US2471134A (en) 1946-07-17 1949-05-24 Standard Oil Dev Co Fractionation apparatus
US3218361A (en) 1960-06-08 1965-11-16 Glidden Co Process for recovering specific isopulegols
GB1503723A (en) 1975-10-14 1978-03-15 Scm Corp Hydrogenation of cyclic unsaturated compounds
US4230533A (en) 1978-06-19 1980-10-28 Phillips Petroleum Company Fractionation method and apparatus
US4338170A (en) * 1979-06-14 1982-07-06 Nissan Chemical Industries, Ltd. Isomerization of β-γ-unsaturated alcohol or its ester
EP0122367A2 (fr) 1983-01-26 1984-10-24 BASF Aktiengesellschaft Colonne de distillation fractionnée
EP0126288A2 (fr) 1983-04-21 1984-11-28 BASF Aktiengesellschaft Procédé d'opération de réactions chimiques et séparation simultanée par distillation d'un mélange en plusieurs fractions au moyen d'une colonne de distillation
EP0133510A1 (fr) 1983-08-03 1985-02-27 BASF Aktiengesellschaft Procédé de séparation par distillation d'un mélange azéotropique
EP0394842A1 (fr) 1989-04-27 1990-10-31 BASF Aktiengesellschaft Catalyseur pour l'hydrogénation de composés aliphatiques insaturés
US5663460A (en) 1994-07-29 1997-09-02 Takasago International Corporation Liquid l-n-menthol composition and process for preparing the same
EP0696572A1 (fr) 1994-08-08 1996-02-14 Basf Aktiengesellschaft Procédé pour la préparation d'amines
EP0992477A1 (fr) 1998-10-07 2000-04-12 Basf Aktiengesellschaft Procédé de préparation de citral
EP1053974A1 (fr) 1999-05-17 2000-11-22 Quest International B.V. Réactions utilisant des acides de Lewis
EP1225163A2 (fr) 2001-01-18 2002-07-24 Takasago International Corporation Procédé de préparation d'isopulégol
EP1318128A2 (fr) 2001-12-07 2003-06-11 Basf Aktiengesellschaft Procédé pour l'hydrogénation de composés carbonyles oléfinquement insaturés
WO2003047749A1 (fr) 2001-12-07 2003-06-12 Basf Aktiengesellschaft Procede d'isomerisation d'alcools allyliques
WO2003048091A2 (fr) 2001-12-07 2003-06-12 Basf Aktiengesellschaft Procede d'isomerisation d'alcools allyliques
DE10223974A1 (de) 2002-05-29 2003-12-11 Basf Ag Isolierung stereoisomerer Isoprenoidalkohole durch Rektifikation
EP1532091A1 (fr) 2002-08-22 2005-05-25 Symrise GmbH & Co. KG Procede pour la production de menthol
WO2004089299A2 (fr) 2003-04-02 2004-10-21 Advancis Pharmaceutical Corporation Antigenes et adjuvants a administration transdermique pulsatile
WO2004101480A1 (fr) 2003-05-13 2004-11-25 Basf Aktiengesellschaft Procédé pour produire des énols cycliques
WO2006040096A1 (fr) 2004-10-11 2006-04-20 Basf Aktiengesellschaft Procede pour preparer des composes de carbonyle optiquement actifs
US7550633B2 (en) 2004-12-22 2009-06-23 Basf Se Method for the production of isopulegol
WO2006092433A1 (fr) 2005-03-03 2006-09-08 Basf Aktiengesellschaft Composes d'aluminium diarylphenoxy
WO2007023109A1 (fr) 2005-08-26 2007-03-01 Basf Se Procede pour preparer de l'isopulegol enrichi
WO2007039342A1 (fr) 2005-09-26 2007-04-12 Symrise Gmbh & Co. Kg Reaction de prins intramoleculaire et catalyseurs appropries
WO2007039366A1 (fr) 2005-09-26 2007-04-12 Symrise Gmbh & Co. Kg Reaction de prins intramoleculaire et catalyseurs appropries (citronellal a isopulegol)
WO2009013192A1 (fr) 2007-07-23 2009-01-29 Basf Se Procédé pour obtenir du menthol par hydrogénation d'isopulégol
WO2009068444A2 (fr) 2007-11-30 2009-06-04 Basf Se Procédé de production de menthol racémique et optiquement actif
WO2016097242A1 (fr) 2014-12-19 2016-06-23 Basf Se Procédé de préparation de composés carbonyle optiquement actifs
RU2579122C1 (ru) 2015-03-25 2016-03-27 Федеральное государственное бюджетное учреждение науки Новосибирский институт органической химии им. Н.Н. Ворожцова Сибирского отделения Российской академии наук (НИОХ СО РАН) Способ получения гераниаля
WO2017060243A1 (fr) 2015-10-05 2017-04-13 Basf Se Procédé pour produire des catalyseurs ruthénium/fer/support de carbone
CN105218312A (zh) 2015-11-03 2016-01-06 山东新和成药业有限公司 一种烯丙基醇经异构化法连续制备芳樟醇的方法
CN107879914A (zh) 2017-11-24 2018-04-06 万华化学集团股份有限公司 一种高效精馏柠檬醛制备橙花醛的方法及用于该方法的催化剂
CN111087343A (zh) 2019-11-29 2020-05-01 万华化学集团股份有限公司 一种羟基吡啶配体及其制备方法和催化应用
WO2021233951A1 (fr) 2020-05-18 2021-11-25 Basf Se Dispositif d'éclairage pour fournir de la lumière à utiliser dans une réaction photochimique
CN112125782A (zh) 2020-09-27 2020-12-25 万华化学集团股份有限公司 一种氢化柠檬醛制备高纯度橙花醇和香叶醛的方法
CN112142583A (zh) 2020-10-26 2020-12-29 万华化学集团股份有限公司 一种香叶醛制备橙花醛的方法
WO2023011951A1 (fr) 2021-08-02 2023-02-09 Basf Se Appareil pour effectuer des réactions photochimiques
CN116474824A (zh) 2023-03-09 2023-07-25 福建森美达生物科技有限公司 一种催化剂、提高柠檬醛中香叶醛含量的方法和装置

Non-Patent Citations (24)

* Cited by examiner, † Cited by third party
Title
ANGEW. CHEM. INT. ED., vol. 43, 2004, pages 994
AY EMEL ET AL: "Citral Photodegradation in Solution: Highlighting of a Radical Pathway in Parallel to Cyclization Pathway", JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY, vol. 67, no. 13, 9 March 2019 (2019-03-09), US, pages 3752 - 3760, XP093116023, ISSN: 0021-8561, DOI: 10.1021/acs.jafc.8b07034 *
B. DUDLEY SULLY ET AL., P.& E.O.R., vol. 1068, pages 235 - 366
CHEM. ENG. TECHNOL., vol. 10, 1987, pages 92 - 98
CHEM.-ING.-TECH., vol. 61, no. 1, 1989, pages 16 - 25
CHEMICAL ENGINEERING, vol. 7, 1997, pages 72 - 76
COOKSON R C ET AL: "The photochemistry of citral", TETRAHEDRON, ELSEVIER SIENCE PUBLISHERS, AMSTERDAM, NL, vol. 19, no. 12, 1 January 1963 (1963-01-01), pages 1995 - 2007, XP026658770, ISSN: 0040-4020, [retrieved on 19630101], DOI: 10.1016/0040-4020(63)85014-0 *
D. DYLONG ET AL., FLAVOUR FRAGR., vol. 37, 2022, pages 195 - 209
DILLING W L: "INTRAMOLECULAR PHOTOCHEMICAL CYCLOADDITION REACTIONS OF NONCONJUGATED OLEFINS", CHEMICAL REVIEWS, AMERICAN CHEMICAL SOCIETY, WASHINGTON, DC, US, 1 January 1966 (1966-01-01), pages 373 - 393, XP008001041, DOI: 10.1021/CR60242A002 *
E. J. LENARDAOG. V. BOTTESELLEF. DE AZAMBUJAG. PERINR. G. JACOB, TETRAHEDRON, vol. 63, 2007, pages 6671 - 6712
GAS SEPARATION AND PURIFICATION, vol. 4, 1990, pages 109 - 114
JÄKEL CPACIELLO R.: "Asymmetric Catalysis on Industrial Scale: Challenges, Approaches, and Solutions", 2010, WILEY-VCH, article "The asymmetric hydrogenation of enones - access to a new L-menthol synthesis", pages: 187 - 205
JENS HOLZ ET AL., ADV. SYNTH. CATAL., vol. 359, 2017, pages 4379 - 4387
O.S. BOKAREVA, COMPUTATIONAL AND THEORETICAL CHEMISTRY, vol. 1149, 2019, pages 8 - 16
PROCESS ENGINEERING, vol. 2, 1993, pages 33 - 34
R. C. COOKSON ET AL., TETRAHEDRON, vol. 19, 1963, pages 1995 - 2007
R.H. PICKARD ET AL., J. CHEM. SOC., 1920, pages 1248 - 1263
STOLLE AGALLERT TSCHMÖGER CONDRUSCHKA B.: "Hydrogenation of citral: a wide-spread model reaction for selective reduction of α,β-unsaturated aldehydes", RSC ADV., vol. 3, no. 7, 2013, pages 2112 - 2153
SYNTHESIS, 1978, pages 147 - 148
TRANS ICHEME, vol. 72, 1994, pages 639 - 644
W. L. DILLING, CHEMICAL REVIEWS, 1966, pages 373 - 393
WOUT A. M. WOLKEN ET AL., J. AGRIC. FOOD CHEM., vol. 48, 2000, pages 5401 - 5405
YUKO IWANAMI ET AL., JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY, vol. 45, 1997, pages 463 - 466
YUKO IWANAMI ET AL: "Changes of Lemon Flavor Components in an Aqueous Solution during UV Irradiation", JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY, vol. 45, no. 2, 1 February 1997 (1997-02-01), pages 463 - 466, XP055040493, ISSN: 0021-8561, DOI: 10.1021/jf960100h *

Similar Documents

Publication Publication Date Title
JP5479320B2 (ja) 光学活性カルボニル化合物の調製方法
CN104854069B (zh) 由6,10‑二甲基十一碳‑5‑烯‑2‑酮或6,10‑二甲基十一碳‑5,9‑二烯‑2‑酮制备的(6r,10r)‑6,10,14‑三甲基十五烷‑2‑酮
JP7005651B2 (ja) ブロモトリクロロメタンを調製する方法
EP2535323A1 (fr) Hydrogénation de cétones disposant d'au moins une liaison double carbone-carbone dans la position gamma-delta
EP2935191B1 (fr) Préparation de (6r,10r)-6,10,14-trimétylpentadécan-2-one à partir de 6,10,3,7-trimétylpentadéca-5,9,13-trién-2-one ou de 3,7-dimétylocta-5,9-dién-2-al
WO2010109650A1 (fr) Procédé de production de 3-méthyl-cyclopentadécénone, procédé de production de r/s-muscone et procédé de production de muscone optiquement active
ES2513540T3 (es) Proceso para preparar amidas de ácidos carboxílicos pirazólicos
Kitahara et al. Synthesis of both the enantiomers of sclerosporin and sclerosporal, sporogenic substance of Sclerotinia fructicola
US9416082B2 (en) Process for the isomerisation of an exo double bond
JP6582324B2 (ja) ６，１０，１４−トリメチルペンタデカ−５，９，１３−トリエン−２−オンまたは６，１０，１４−トリメチルペンタデカ−５，９−ジエン−２−オンから調製した（６ｒ，１０ｒ）−６，１０，１４−トリメチルペンタデカン−２−オン
WO2025011972A1 (fr) Photoisomérisation de géranial et de neral
EP2935189A1 (fr) Utilisation de mélanges d'isomères e/z en vue d'obtenir des produits spécifiques de manière quantitative par combinaison d'hydrogénation asymétrique et d'isomérisation
CN101070270B (zh) (e,e)-香叶基芳樟醇的合成方法
EP2935190B1 (fr) (6r,10r) -6,10,14-triméthylpentadécan-2-one préparé à partir de 6,10-diméthylundéca-3,5,9-trién-2-one
WO2014097172A1 (fr) Monoxyde d'azote à titre de catalyseur d'isomérisation cis/trans pour composés insaturés
EP2935176B1 (fr) (6r, 10r) -6,10,14-trimétylpentadecan-2-one préparé à partir de (r)-3,7-dimetyloct-6-enal
US7002049B2 (en) Process for α,β-dihydroxyalkenes and derivatives
Jung et al. Diastereoselective organocuprate addition to homochiral ketals of 3-acetylcyclopent-2-en-1-one
JP3281532B2 (ja) トランス−３−イソカンフィルシクロヘキサノールの製造法
Eliel et al. The conformational energy of the (benzene) chromium tricarbonyl substituent
US20250236576A1 (en) Process
EP2935175B1 (fr) (6r, 10r) -6,10,14-trimétylpentadecan-2-one préparé à partir de (r)-6,10,14-trimetylpentadec-5-en-2-one

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 24737903

Country of ref document: EP

Kind code of ref document: A1