DE2032709A1 - 2-halo-3-mercapto-maleicaldehydeacids as photo-hardeners - from mucohaloacids and mercaptans with bases in inert solvents - Google Patents

Abstract

Title cpds. have formula (R1,R2 = H, C1-12 alkyl, C2-12 alkenyl, C5-12 cycloalkyl, C7-12 aralkyl or aryl; X = halogen) are starters for dyes and pesticides. Prepn. from the corresp. 2,3-dihalo-cpds. with mercaptans and a base (org. or inorg) in inert org. solvents gives good yields of pure 2-halo-cpds. practically without-3-halo isomers. In an example 173 parts (71%) 2-chloro-3-phenyl-mercapto-maleic aldehyde-acid, m.pt. 160-162 degrees are obtd. from 169 parts mucochloric acid and 110 parts thiophenol with 59 parts isorpopylamine in acetone.

Description

Process for the preparation of 2-halo-3-mercapto-maleic aldehyde acid compounds The invention relates to a process for the preparation of 2-halo-3-mercapto-maleic aldehyde compounds by reacting mucohalogenic acid compounds with sulfur compounds and a basic compound.

It is known that the 2-phenylmercapto-3-halo-maleic aldehyde acids can be prepared by reacting mucohalogenic acids with thiophenol in the presence of alkali (Belgian patent 725 964). From the examples (2.25 mol of potassium hydroxide to 1 mol of mucochloric acid in the case of Example 3) it is evident that it is not the mucochalic acids themselves, but the alkali salts of the mucohalic acids with the alkali azene of the mercaptans and the salts of the 2-pheny.lmercapto-3- halogen-maleic aldehyde acids react, which are then converted into 2-phenylmercapto-3-halogenated maleic aldehyde acids by acidification. In the case of mucochloric acid, the reaction can be formulated as follows: It has now been found that 2-halo-3-mercapto-maleic aldehyde acid compounds of the general formula can be obtained in which R1 and R2 can be the same or different and each represent a hydrogen atom, an aliphatic, cycloaliphatic, araliphatic or aromatic radical and X denotes a halogen atom, by reacting mucohalic acid compounds with sulfur compounds and a basic compound advantageously obtained when mucohalic acid compounds of the general formula in which X and R1 have the aforementioned meaning9 with sulfur compounds of the general formula 2-SH III, in which R2 has the aforementioned meaning, and a basic compound in an amount of less than 1.5 times the equivalent weight, based on starting material II .

In the case of using mucochloric acid, trietbylsmin and thiophenol, the reaction can be represented by the following formulas: In view of the prior art, the process according to the invention surprisingly and simply provides a large number of the new 2-halo-3-mercapto-maleic aldehyde compounds in good yield and purity. It could not be expected that with the aid of the process 2-halo-3-mercapto and not 3-halo-2-mercapto compounds can be prepared with the advantageous results mentioned and without substantial formation of 3-halogen compounds .

Starting material II is stoichiometric with starting material III Amount or with an excess of starting material III, preferably in a molar ratio from 1 to 10 moles of starting material III per 1 mole of starting material II. Preferred Starting materials II and III and accordingly preferred end materials I are those in the formulas of which R1 and R2 can be the same or different and in each case a hydrogen atom, an alkyl radical with 1 to 12 carbon atoms, an alkenyl radical with 2 to 12 carbon atoms, a cycloalkyl radical with 5 to 12 carbon atoms, an aralkyl radical with 7 to 12 carbon atoms or a phenyl radical and X is a chlorine atom or a Called bromine atom. The residues mentioned can still be carried out under the reaction conditions inert groups and / or atoms, e.g. 3. Alkyl, alkoxy groups with 1 to 4 carbon atoms, Chlorine atoms, hydroxyl groups, dialkylamino groups with 1 to 4 carbon atoms each Alkyl radical, be substituted.

For example, the following starting materials II can be used: Mucochloric acid, Muobromic acid, nuco-chloro-bromic acid; analogous methyl, ethyl, cyclohexyl, benzyl, Phenyl esters of mucohalogenic acids.

The starting materials III are, for example: hydrogen sulfide, Ethyl mecarptan, ß-hydroxyethyl mercaptan, ß-diethylaminoethyl mercaptan, trichloroallyl mercaptan, Lauryl mercaptan, cyclohexyl mercaptan, cyclododecyl meroaptan, 2,3, 6-trichlorobenzyl mercaptan, p-methoxythiophenol, p-tert-butylthiophenol, thiophenol, p-chlorothiophenol.

Starting materials II and III are with a basic compound in an amount less than 1.5 times, preferably 0.6 to 1.4 times, in particular 0.9 to 1.1 times the equivalent weight, based on the starting material II implemented. Preferred basic compounds are primary, secondary and in particular tertiary amines, alkaline earth, zinc and especially alkali compounds and corresponding Mixtures. Advantageous alkali, zinc and alkaline earth compounds are the hydroxides, Oxides, carbonates, bicarbonates, salts of weak or polybasic acids, alcoholates of calcium, barium, zinc, lithium and especially sodium and galium, there come E.g. as basic compounds in question: potassium hydroxide, sodium hydroxide, potassium carbonate ', Sodium carbonate, lithium carbonate, sodium bicarbonate, potassium bicarbonate, calcium hydroxide, Barium oxide, calcium carbonate, zinc oxide, sodium acetate, propionate, ethylene glycolate, methylate, ethylate, tripropylene glycolate, trimethylamine, triethylamine, pyridine, Diethylaniline, dimethylaminoethanol, N-ethylpiperidine, N-methylpyrrolidine, ethylamine, , Diethylamine, aniline, N-methylaniline, benzylamine, cyclohexylamine, di-tert.-butylamine, Isopropylamine.

The reaction is usually carried out at a temperature between -30 to + 1500C, preferably between -10 to +120 0, under reduced or increased pressure or preferably carried out without pressure, continuously or discontinuously. Solvents which are inert under the reaction conditions are expediently used, e.g. aromatic, aliphatic and cycloaliphatic hydrocarbons such as benzene, toluene, Xylene, ligroin, hexane, heptane, cyclohexane, cyclooctane; Chlorinated hydrocarbons such as Carbon tetrachloride, chloroform, methylene chloride, chlorobenzene; Ether like diethyl ether, Dipropyl ether, tetrahydrofuran, dioxane; Esters such as ethyl acetate, butyl acetate; Ketones such as acetone, diethyl ketone, ethyl methyl ketone, cyclohexanone; Alcohols such as methanol, Isopropanol, tert-butanol, ethylhexanol, cyclohexanol; Nitriles such as acetonitrile; Carboxamides such as formamide, dimethylformamide, acetamide, tetramethylurea, Dimethylformamide, acetamide, tetramethylurea; Dimethyl sulfoxide, water; or corresponding mixtures. The solvent generally comes in an amount of 100 to 1,000 percent by weight, based on starting material II, in use.

The reaction can be carried out as follows. Rin mixture of Starting material II, III and basic compound, expediently in a solvent dissolved or suspended, is for / 4 to 12 hours with thorough mixing held at the reaction temperature. The end product is then converted from the mixture into in a conventional manner, for example by filtration, concentration of the filtrate and renewed filtration isolated. It can also optionally take the solvent from the reaction mixture removed and the residue partitioned between water and an organic solvent , the end product being obtained when the organic phase is concentrated. Of the The end product is generally obtained in pure form, but can be used if necessary from a suitable solvent, see B. Toluene, ligroin, ethyl acetate, acetone or their mixtures, are recrystallized.

The novel compounds which can be prepared by the process of the invention are hardeners for photographic gelatin layers (see Example 14) and are valuable Raw materials for the manufacture of dyes and pesticides.

Reaction with monosubstituted hydrazines gives e.g. from them the pyridazone derivatives described in German Offenlegungsschrift 1 445 475, are the means of influencing plant growth.

The parts given in the examples are parts by weight.

Example 1 169 parts of nucochloric acid and 120 parts of thiophenol in 1 000 parts of acetone are at 20 to 3000 with a solution of 59 parts of isopropylamine slowly added in 200 parts of acetone. The mixture is refluxed for one hour heated, the solvent was then distilled off and the remaining residue distributed between 5,000 parts of water and 20,000 parts of methylene chloride.

The organic phase is separated off, dried over sodium sulfate, concentrated and the residue was recrystallized from benzene. Yield: 173 parts (71 up to 72% of theory) 2-chloro-3-phenylmercapto-maleic aldehyde acid of melting point 160 to 162 ° C.

Example 2 338 parts of mucochloric acid in 1,000 parts of acetone at 20 to 300C with a suspension of 56 parts of calcium oxide in a solution of 220 parts of thiophenol in 700 parts of acetone are added. The mixture is an hour heated to reflux and then the solvent is distilled off. The remaining one The residue is partitioned between 7,000 parts of water and 3Q,000 parts of methylene chloride and the organic phase is separated off, dried over sodium sulfate and concentrated. The residue is recrystallized from benzene. Yield of 2-chloro-3-phenylationcapto-maleic aldehyde acid: 334 parts (69% of theory) with a melting point of 161 to 162 ° C.

Example 3 169 parts of mucochloric acid and 101 parts of triethylamine are used dissolved in 3,000 parts of ethanol. These are quickly added 68 parts of ithyl mercaptan and the mixture is then refluxed for 10 hours. The alcohol is distilled off and the residue is distributed between 1,000 parts of water and 4,000 parts of ether. The ethereal phase provides 45 parts (77% of theory) of 2-chloro-3-ethylmercapto-maleic aldehyde acid on concentration, which, recrystallized from toluene / ligroin, melts at 104 to 105 ° C.

Example 4 169 parts of mucochloric acid and 177 parts of trichloroallyl mercaptan are dissolved in 2,500 parts of ethanol and treated with 101 parts of riethylamine. at the temperature rises to 45 ° C. during the reaction. After 7 hours of heating, the alcohol becomes distilled off and the residue between 900 parts of water and 9,000 parts of methylene chloride distributed. After concentration, the organic phase yields 183 parts (59% of theory) crystalline 2-chloro-3-trichloroallylmercapto-malealdehyde acid. M.p. 58 to 60 ° C (from cyclohexane / toluene).

Example 5 169 parts of mucochloric acid, 101 parts of triethylamine and 78 parts Parts of B-mercaptoethanol are refluxed in 3,000 parts of acetone for 2 hours. The mixture is filtered off with suction and the filtrate obtained on concentrating the filtrate is crystallized and dried residue from toluene. Yield 112 parts (53% of theory) 2-chloro-3-hydroxyethylmercapto-maleic aldehyde acid. Mp 127-128 ° C.

Example 6 848 parts of β-mercaptoethyl diethylamine hydrochloride are used dissolved in methanol and 885 parts of 30 percent sodium methylate solution at room temperature admitted. The methanol is distilled off and the residue is taken up in acetone and the mixture is filtered. The resulting solution becomes a solution of 845 Parts of mucochloric acid in methanol and heated under reflux for 4 hours. At the Concentration of the mixture gives a crystallizate which with 400 parts of chloroform is stirred out and suctioned off. Yield 97 parts (64 ffi of theory) of hydrochloride of 2-chloro-3-diethylamino-ethylmercapto-maleic aldehyde acid.

Mp. 126 to 12800.

Example 7 169 parts of mucochloric acid, 101 parts of triethylamine and 202 parts Parts of lauryl mercaptan are refluxed in 3000 parts of ethanol for 10 hours. The alcohol is distilled off and the residue between 700 parts of water and 3 500 parts of methylene chloride distributed. The organic phase delivers after concentration 23 parts (79% of theory) of 2-chloro-3-laurylmercaptomaleic aldehyde acid. Fp. 65 to 660C (from petroleum ether).

Example 8 To 169 parts of mucochloric acid and 227.5 parts of 2,3,6-trichlorobenzyl mercaptan 101 parts of triethylamine are added to 3,200 parts of ethanol. The increases Temperature of the reaction mixture to 45 0C. The mixture is refluxed for 7 hours and then distills off the alcohol. The residue is mixed with water and the aqueous phase extracted with methylene chloride. The organic phase will dried over sodium sulfate and upon concentration yields 2-chloro-3- (2 ', 3', 6'-trichlorobenzylmercapto) -maleic aldehyde, which, recrystallized from cyclohexane / toluene, melts at 138 to 1390C. yield 243 parts (67 ffi of theory).

Example 9 169 parts of mucochloric acid and 110 parts of thiophenol in 2 500 parts of acetone are mixed with 101 parts of triethylamine and 30 minutes on Heated to reflux. After concentration, the residue is stirred with 1,500 parts of water and dried. Yield of 2-chloro-3-phenylmercapto-maleic aldehyde acid: 237 parts (98 ffi of theory). M.p. 161 to 1630C (from benzene).

Example 10 A solution of 169 parts of mucochloric acid, 101 parts riethylamine and 140 parts of p-methoxy-thiophenol in 2,000 parts of ethanol for 3 hours heated to reflux. The alcohol is distilled off and the residue between water and methylene chloride distributed. The organic phase gives a residue on concentration, which is recrystallized from toluene / ligroin.

Yield of 2-chloro-3- (p-methoxyphenylmereapts) -aldehydature: 240 Parts (88% of theory), m.p. 102-1040C.

Example 11 To a solution of 258 parts of mucobromic acid in 15,000 Parts of ethanol become a mixture of 116 parts of cyclohexyl with stirring mercaptan and 56 parts of potassium hydroxide in 10,000 parts of ethanol. The mixture will stirred at room temperature for 6 hours, then filtered off with suction and the solvent removed. The residue is extracted with 4,000 parts of methylene chloride and the methylene chloride solution freed from solvent in vacuo. The residue of 2-bromo-3-cyclohexylmercaptomeleinaldehyde acid is recrystallized from benzene. Yield: 795 parts (67% of theory), melting point 147 up to 14800.

Example 12 197 parts of ethyl mucochlorate are used in 1,600 parts Dissolved acetone and at the same time with 101 parts of triethylamine and 110 parts of thiophenol slowly shifted. Then the mixture is stirred at room temperature for 12 hours, the acetone is distilled off in vacuo and the residue taken up in water with Shaken out methylene chloride. After concentration, the organic phase provides one 179 parts of residue recrystallized from ligroin with the addition of animal charcoal of ethyl α-chloro-β-phenylmercapto-maleinaldehydate (66% of theory) from the melting point 49 to 500C supplies.

Example 13 169 parts of mucochloric acid are mixed with 1,200 parts of water completely dissolved at 60 ° E. It now becomes a mixture at 60.degree. C. with stirring. from 110 parts of thiophenol and 56 parts of potassium hydroxide in 500 parts of water were added. The mixture is then heated to 80 ° C. for 4 hours. After cooling down, become the crystals formed are suctioned off, dried and from a benzene / cyclohexane mixture recrystallized with the addition of animal charcoal.

Yield of α-chloro-ß-phenylmercapto-maleic aldehyde acid 110 Parts (45% of theory) from melting point 160 to 1620a.

Example 14 (Use) 70 to 80 g of gelatin are mixed with water 1 kg of an aqueous gelatin solution prepared and in this 10-3 to 4 # 10-3 mol α-Chlor-ß-mercapto-maleinaldehydic acid are stirred in with this solution Triacetate cellulose-based films are coated in such a way that the gelatin layer appears drying is 10 µ.

It is dried for 2, 69, 10 and 14 days at room temperature. The measurement the melting point of the gelatin; which is a measure of the hardening is now easy carried out in such a way that the film strips coated with the gelatin in a 2 percent aqueous soda solution, the temperature of which is increased by 1 ° C per minute, dives.

Whereas with untreated gelatine the melting point is practically independent of the selected drying time is between 32 and 35 ° C, is the melting point those treated with α-chloro-ß-mercaptomaleic aldehyde acid, depending on the compound and drying time, at up to 74 ° C. The usual photographic additives interfere the hardening process is not practical0

Claims (2)

Process for the preparation of 2-halo-3-mercapto-maleic aldehyde acid compounds of the general formula in which R1 and R2 can be the same or different and each represent a hydrogen atom, an aliphatic, cycloaliphatic, araliphatic or aromatic radical and X denotes a halogen atom, by reacting mucohalogen acid compounds with sulfur compounds and a basic compound, characterized in that mucohalogen acid compounds of the general formula in which X and R1 have the aforementioned meaning, with sulfur compounds of the general formula R2-SH III, in which R2 has the aforementioned meaning, and a basic compound in an amount of less than 1.5 times the equivalent weight, based on starting material II . 2. 2-halo-3-mercapto-maleic aldehyde compounds of the general formula in which R1 and R2 can be the same or different and each denotes a hydrogen atom, an aliphatic, cycloaliphatic, araliphatic or aromatic radical and 1 denotes a halogen atom.