GB2111044A - Process for the production of cimetidine - Google Patents
Process for the production of cimetidine Download PDFInfo
- Publication number
- GB2111044A GB2111044A GB08137175A GB8137175A GB2111044A GB 2111044 A GB2111044 A GB 2111044A GB 08137175 A GB08137175 A GB 08137175A GB 8137175 A GB8137175 A GB 8137175A GB 2111044 A GB2111044 A GB 2111044A
- Authority
- GB
- United Kingdom
- Prior art keywords
- process according
- reaction
- compound
- formula
- general formula
- 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.)
- Granted
Links
- 238000000034 method Methods 0.000 title claims abstract description 34
- 229960001380 cimetidine Drugs 0.000 title claims abstract description 14
- CCGSUNCLSOWKJO-UHFFFAOYSA-N cimetidine Chemical compound N#CNC(=N/C)\NCCSCC1=NC=N[C]1C CCGSUNCLSOWKJO-UHFFFAOYSA-N 0.000 title abstract 2
- 238000004519 manufacturing process Methods 0.000 title description 4
- -1 aliphatic radical Chemical class 0.000 claims abstract description 16
- 150000001875 compounds Chemical class 0.000 claims abstract description 16
- 125000004432 carbon atom Chemical group C* 0.000 claims abstract description 8
- 125000000217 alkyl group Chemical group 0.000 claims abstract description 4
- 238000002360 preparation method Methods 0.000 claims abstract description 4
- 238000006243 chemical reaction Methods 0.000 claims description 25
- AQIXAKUUQRKLND-UHFFFAOYSA-N cimetidine Chemical compound N#C/N=C(/NC)NCCSCC=1N=CNC=1C AQIXAKUUQRKLND-UHFFFAOYSA-N 0.000 claims description 12
- ISWSIDIOOBJBQZ-UHFFFAOYSA-N Phenol Chemical compound OC1=CC=CC=C1 ISWSIDIOOBJBQZ-UHFFFAOYSA-N 0.000 claims description 9
- XZMCDFZZKTWFGF-UHFFFAOYSA-N Cyanamide Chemical compound NC#N XZMCDFZZKTWFGF-UHFFFAOYSA-N 0.000 claims description 8
- 239000003960 organic solvent Substances 0.000 claims description 7
- 239000000203 mixture Substances 0.000 claims description 6
- JMANVNJQNLATNU-UHFFFAOYSA-N glycolonitrile Natural products N#CC#N JMANVNJQNLATNU-UHFFFAOYSA-N 0.000 claims description 5
- 239000012022 methylating agents Substances 0.000 claims description 5
- 150000003254 radicals Chemical class 0.000 claims description 4
- 150000003512 tertiary amines Chemical class 0.000 claims description 4
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 claims description 3
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 claims description 3
- 229910052736 halogen Inorganic materials 0.000 claims description 3
- 150000002367 halogens Chemical class 0.000 claims description 3
- RAXXELZNTBOGNW-UHFFFAOYSA-N imidazole Natural products C1=CNC=N1 RAXXELZNTBOGNW-UHFFFAOYSA-N 0.000 claims description 3
- 230000001035 methylating effect Effects 0.000 claims description 3
- 150000007530 organic bases Chemical class 0.000 claims description 3
- 238000010992 reflux Methods 0.000 claims description 3
- 229910021653 sulphate ion Inorganic materials 0.000 claims description 3
- QTWJRLJHJPIABL-UHFFFAOYSA-N 2-methylphenol;3-methylphenol;4-methylphenol Chemical compound CC1=CC=C(O)C=C1.CC1=CC=CC(O)=C1.CC1=CC=CC=C1O QTWJRLJHJPIABL-UHFFFAOYSA-N 0.000 claims description 2
- CPELXLSAUQHCOX-UHFFFAOYSA-M Bromide Chemical compound [Br-] CPELXLSAUQHCOX-UHFFFAOYSA-M 0.000 claims description 2
- 229930003836 cresol Natural products 0.000 claims description 2
- 150000007529 inorganic bases Chemical class 0.000 claims description 2
- 101100109871 Neurospora crassa (strain ATCC 24698 / 74-OR23-1A / CBS 708.71 / DSM 1257 / FGSC 987) aro-8 gene Proteins 0.000 claims 4
- 239000012948 isocyanate Substances 0.000 claims 3
- 150000002513 isocyanates Chemical class 0.000 claims 3
- KJCVRFUGPWSIIH-UHFFFAOYSA-N 1-naphthol Chemical compound C1=CC=C2C(O)=CC=CC2=C1 KJCVRFUGPWSIIH-UHFFFAOYSA-N 0.000 claims 1
- 125000000022 2-aminoethyl group Chemical group [H]C([*])([H])C([H])([H])N([H])[H] 0.000 claims 1
- 230000003197 catalytic effect Effects 0.000 claims 1
- 239000003153 chemical reaction reagent Substances 0.000 claims 1
- 238000006482 condensation reaction Methods 0.000 claims 1
- 125000005843 halogen group Chemical group 0.000 claims 1
- 150000002440 hydroxy compounds Chemical class 0.000 claims 1
- 150000002460 imidazoles Chemical class 0.000 claims 1
- 125000002256 xylenyl group Chemical class C1(C(C=CC=C1)C)(C)* 0.000 claims 1
- 150000001412 amines Chemical class 0.000 abstract description 2
- 239000000047 product Substances 0.000 description 16
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 description 13
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 9
- ZMANZCXQSJIPKH-UHFFFAOYSA-N Triethylamine Chemical compound CCN(CC)CC ZMANZCXQSJIPKH-UHFFFAOYSA-N 0.000 description 9
- 238000007069 methylation reaction Methods 0.000 description 9
- 230000011987 methylation Effects 0.000 description 7
- RTZKZFJDLAIYFH-UHFFFAOYSA-N Diethyl ether Chemical compound CCOCC RTZKZFJDLAIYFH-UHFFFAOYSA-N 0.000 description 6
- 238000009833 condensation Methods 0.000 description 5
- 230000005494 condensation Effects 0.000 description 5
- 235000019441 ethanol Nutrition 0.000 description 5
- 150000002825 nitriles Chemical class 0.000 description 4
- 239000002904 solvent Substances 0.000 description 4
- ZWEHNKRNPOVVGH-UHFFFAOYSA-N 2-Butanone Chemical compound CCC(C)=O ZWEHNKRNPOVVGH-UHFFFAOYSA-N 0.000 description 3
- KFZMGEQAYNKOFK-UHFFFAOYSA-N Isopropanol Chemical compound CC(C)O KFZMGEQAYNKOFK-UHFFFAOYSA-N 0.000 description 3
- 238000004821 distillation Methods 0.000 description 3
- 150000002148 esters Chemical class 0.000 description 3
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- LSDPWZHWYPCBBB-UHFFFAOYSA-N Methanethiol Chemical compound SC LSDPWZHWYPCBBB-UHFFFAOYSA-N 0.000 description 2
- BAVYZALUXZFZLV-UHFFFAOYSA-N Methylamine Chemical compound NC BAVYZALUXZFZLV-UHFFFAOYSA-N 0.000 description 2
- LRHPLDYGYMQRHN-UHFFFAOYSA-N N-Butanol Chemical compound CCCCO LRHPLDYGYMQRHN-UHFFFAOYSA-N 0.000 description 2
- 239000007795 chemical reaction product Substances 0.000 description 2
- 239000003795 chemical substances by application Substances 0.000 description 2
- 238000002425 crystallisation Methods 0.000 description 2
- 230000008025 crystallization Effects 0.000 description 2
- 150000002170 ethers Chemical class 0.000 description 2
- 238000001640 fractional crystallisation Methods 0.000 description 2
- IWDCLRJOBJJRNH-UHFFFAOYSA-N p-cresol Chemical compound CC1=CC=C(O)C=C1 IWDCLRJOBJJRNH-UHFFFAOYSA-N 0.000 description 2
- BWHMMNNQKKPAPP-UHFFFAOYSA-L potassium carbonate Chemical compound [K+].[K+].[O-]C([O-])=O BWHMMNNQKKPAPP-UHFFFAOYSA-L 0.000 description 2
- 239000000376 reactant Substances 0.000 description 2
- KUFFULVDNCHOFZ-UHFFFAOYSA-N 2,4-xylenol Chemical compound CC1=CC=C(O)C(C)=C1 KUFFULVDNCHOFZ-UHFFFAOYSA-N 0.000 description 1
- QGZKDVFQNNGYKY-UHFFFAOYSA-O Ammonium Chemical compound [NH4+] QGZKDVFQNNGYKY-UHFFFAOYSA-O 0.000 description 1
- 102000003710 Histamine H2 Receptors Human genes 0.000 description 1
- 108090000050 Histamine H2 Receptors Proteins 0.000 description 1
- 229910019142 PO4 Inorganic materials 0.000 description 1
- 208000007107 Stomach Ulcer Diseases 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 239000000739 antihistaminic agent Substances 0.000 description 1
- 229940125715 antihistaminic agent Drugs 0.000 description 1
- VUEDNLCYHKSELL-UHFFFAOYSA-N arsonium Chemical compound [AsH4+] VUEDNLCYHKSELL-UHFFFAOYSA-N 0.000 description 1
- 125000003118 aryl group Chemical group 0.000 description 1
- 239000003054 catalyst Substances 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 150000003983 crown ethers Chemical class 0.000 description 1
- ATDGTVJJHBUTRL-UHFFFAOYSA-N cyanogen bromide Chemical compound BrC#N ATDGTVJJHBUTRL-UHFFFAOYSA-N 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000003344 environmental pollutant Substances 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 230000008020 evaporation Effects 0.000 description 1
- 239000000284 extract Substances 0.000 description 1
- 239000012467 final product Substances 0.000 description 1
- 201000005917 gastric ulcer Diseases 0.000 description 1
- 150000004820 halides Chemical class 0.000 description 1
- 229910052500 inorganic mineral Inorganic materials 0.000 description 1
- INQOMBQAUSQDDS-UHFFFAOYSA-N iodomethane Chemical compound IC INQOMBQAUSQDDS-UHFFFAOYSA-N 0.000 description 1
- RHMQNXNXUZLEIY-UHFFFAOYSA-N methanol;2-propan-2-yloxypropane Chemical compound OC.CC(C)OC(C)C RHMQNXNXUZLEIY-UHFFFAOYSA-N 0.000 description 1
- 125000002496 methyl group Chemical group [H]C([H])([H])* 0.000 description 1
- 239000011707 mineral Substances 0.000 description 1
- 238000006386 neutralization reaction Methods 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 238000003408 phase transfer catalysis Methods 0.000 description 1
- 235000021317 phosphate Nutrition 0.000 description 1
- 150000004714 phosphonium salts Chemical class 0.000 description 1
- 150000003013 phosphoric acid derivatives Chemical class 0.000 description 1
- 231100000719 pollutant Toxicity 0.000 description 1
- 229910000027 potassium carbonate Inorganic materials 0.000 description 1
- BDERNNFJNOPAEC-UHFFFAOYSA-N propan-1-ol Chemical compound CCCO BDERNNFJNOPAEC-UHFFFAOYSA-N 0.000 description 1
- 239000011541 reaction mixture Substances 0.000 description 1
- 238000004064 recycling Methods 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 238000003756 stirring Methods 0.000 description 1
- 150000003871 sulfonates Chemical class 0.000 description 1
- 150000003467 sulfuric acid derivatives Chemical class 0.000 description 1
- 230000001225 therapeutic effect Effects 0.000 description 1
- ILWRPSCZWQJDMK-UHFFFAOYSA-N triethylazanium;chloride Chemical compound Cl.CCN(CC)CC ILWRPSCZWQJDMK-UHFFFAOYSA-N 0.000 description 1
- 239000002351 wastewater Substances 0.000 description 1
- 150000003739 xylenols Chemical class 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07D—HETEROCYCLIC COMPOUNDS
- C07D233/00—Heterocyclic compounds containing 1,3-diazole or hydrogenated 1,3-diazole rings, not condensed with other rings
- C07D233/54—Heterocyclic compounds containing 1,3-diazole or hydrogenated 1,3-diazole rings, not condensed with other rings having two double bonds between ring members or between ring members and non-ring members
- C07D233/64—Heterocyclic compounds containing 1,3-diazole or hydrogenated 1,3-diazole rings, not condensed with other rings having two double bonds between ring members or between ring members and non-ring members with substituted hydrocarbon radicals attached to ring carbon atoms, e.g. histidine
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
New process for the preparation of Cimetidine from an amine of the formula <IMAGE> and from a compound of the formula: <IMAGE> in which Ar=aliphatic radical with 3-6 C atoms or aromatic radical simple or containing alkyl groups having 1-3 C atoms.
Description
SPECIFICATION
Process for the production of cimetidine
The present invention relates to a new process for the production of N-cyano-N '-methyl-N"-2-[(5-methyl-l H- imidazol-4-yl)-methyl-thio-ethyl]-guanidine commonly known as Cimetidine, of the formula:
therapeutical product, which has reached considerable importance during these last years as anti-histaminic agent for H2 receptors, particularly in the treatment of the gastric ulcer.
Several processes have been suggested for the preparation of Cimetidine, but most of them have a merely theoretical interest or can be accomplished only on a laboratory scale. The only process, which is at present realized on industrial scale with good yields, is represented by the following reaction scheme:
As it is shown above both in the first and in the second stage of this process, stoichiometric amounts of volatile methyl-mercaptan are produced, a highly polluting compound, having disagreable odour, which can be trapped with difficulty.
Moreoverthe third methylation stage requires the use of methylamine in strong excess (about 6:1 as molar ratio), and this excess can be removed with difficulty from the waste waters, which contain it. Also in this case the compound involved is a bad smelling pollutant, which causes serious ecological problems.
Now we have found a new production process for Cimetidine, object of the present invention, which can be realized industrially with high yields and does not not involve particular industrial problems and above all does not cause the pollution effects of the best known process described above.
The new process, which is object of the present invention, is represented schematicaliy by the following reaction sequence:
A) Ar-OH + XCN < Ar-OCN + HX
in which Ar= aliphatic radical having 3-6 C atoms or aromatic radical simple or containing alkyl groups with 1-3 C atoms; X=halogen, preferably Cl, Br.
in which Ar is as specified above
in which Ar is as specified above and Y is the radical of any suitable methylating agent, as halogen, sulphate, sulfonic, phosphoric and similar radicals.
D)
in which Ar is as specified above.
The stage A is carried out by using the reactants in stoichiometric ratio, in solution of inert organic solvent, and in the presence of a stoichiometric amount of an organic or inorganic base, preferably a tertiary amine, suitable to neutralize the halogenidric formed in the reaction.
The compound Ar-OH can be an aliphatic primary alcohol, as, for example, propanol, butanol and similar ones, or an aromatic monophenol, as, for example, phenol, cresol, xylenol, naphtol and similar ones.
Nevertheless it was found that the best results as regards yields, reaction selectivity and purity of the final product, are obtained by using monophenols and, in particular, phenol.
Moreover the phenol reacts under milder conditions and it can be recovered and recycled more easily in the final stage (D).
The organic solvents used in preference in the stage (A) are : acetone, methylethylketone, ethyl alcohol and similar ones, at temperatures between 0 and 20"C. The cyanogen halide can be, as indicated above, the chloride or bromide with equivalent effectiveness. In any case the yields are above 90% in this stage and in general they are practically quantitative, and consequently the residual cyanogen halide in the reacted mixture is very low. The reaction product can be separated by distillation as very pure compound, or, after removal of the precipitated halide salt and distillation of the solvent, it can be used as raw product in the subsequent stage. The stage (B) is carried out in inert organic solvents like alcohols ketones, ethers, esters, in the presence of catalitic amounts of a strong base, preferably a tertiary amine.
The cyanic ester and the cyanamide are preferably used in stoichiometric ratio. The yields are always above 90% and the reaction product is a crystalline solid, which crystallizes directly from the reaction mixture or can be separated easily by evaporation of the solvent. The reaction is carried out preferably at room temperature.
The methylation reaction (C) can be realized by means of any methylating agent, as halides, sulphates, sulfonates, phosphates, etc. both directly in organic solvent in the presence of a basic agent for the neutralization of the mineral acid formed in the reaction, and by means of phase transfer catalysis in the presence of ammonium, arsonium or phosphonium salts, or in the presence of crown ethers. It was surprisingly found that in any case the nitrogen of the = NH group is much more active towards the methylating agents and consequently the mono-methylation reaction occurs with high selectively only at this group, allowing to obtain good yields of the wanted mono-methyl derivative.
Moreover it was found that it is convenient to carry out the methylations with partial conversions, preferably with conversions between 40 and 80%, recovering and recycling the unreacted product by a simple fractional crystallization, in order to minimize the amount of dimethylderivative possibly formed.
Obviously the methylation conditions used are those corresponding to the methylation method chosen.
Generally the methylating agent is used in amounts between 50 and 100% of the stoichiometric quantity.
Also the final condensation (D), producing Cimetidine, is carried out in inert organic solvent, preferably selected from the group including alcohol, ethers, esters, in the presence of an organic base as catalyst, using stoichiometric ratios of the reactants. The compound 4-methyl-5-(2-aminomethyl)-thiomethylimidazole is prepared according to the known methods.
The condensation occurs at the reflux temperature, with yields nearly quantitative on the converted product. The unreacted nitrile and imidazolic base are separated by crystallization and recycled. The total yield of the process is about 70% as pure product. In order to allow an easier repetition of the process according to the present invention, we report some examples of execution, which will better illustrate some possible operative conditions, without, however, limiting the possible alternatives, which are reported in the patent specification and are immediately evident for those skilled in the art.
Example 1
130 g of CICN are added at O"C to a solution of 188 g of phenol in 500 ml of acetone. Under stirring and cooling, 203 g of triethylamine are added so as to keep the temperature between 0" and 1 0'C. The mixture is stirred for further 15 minutes, the precipitated triethylamine hydrochloride is separated, which is washed with acetone and recovered. The collected acetone extracts are distilled in order to recover the solvent; a residue remains, which is dissolved in 1500 ml of ether; 90g of cyanamide and 10g of triethylamine are added. 202g of product with m.p. 158"C crystallize after 10 hours.- By concentration of the ether solution other 87 g of pure product crystallize (yield 90%).
289 g of the product thus obtained are dissolved in 1700 ml of acetone, 280g of potassium carbonate and 869 of methyl jodide are added. The mixture is heated at 40"C for 6 hours.
Acetone is recovered by distillation; by fractional crystallization from ethyl ether, the residue provides 11 6g of N-methylderivative with m.p. 121"C and 1459 of unreacted starting product, which is recovered and recycled.
Conversion 50%; yield on the converted product: 74%.
A solution of 41 g of dihydrochloride of 4-methyl-5-(2-aminoethyl)-thiomethyl-imidazole in 200 ml of ethanol is added drop by drop to a solution of 309 of N-methyl-derivative and 359 of triethylamine in 300 ml ethanol heated at the reflux temperature.
The mixture is refluxed for two hours and the solvent is evaporated. A mixture remains, which contains 21,5 g of C polymorphous Cimetidine, 10,5 g of unreacted nitrile and 14,2 g of imidazolic base; the A polymorphous Cimetidine is obtained by crystallization from isopropyl ether-methanol. The unreacted nitrile and imidazolic base are recycled. The conversion is 51%. The yield on the converted nitrile is 85%.
The yield on the converted imidazolic base is 98%
Example 2
The procedure of Example 1 was repeated, using cyanogen bromide instead of the chloride, with the same soichiometric ratios. The reaction provides results, which are practically identical. The yield of cyanamide with m.p. 158"C (phase B) is 91%, which is afterwards treated exactly as described in the Example 1.
Example 3
The procedure of Example 1 was repeated, using p-cresol instead of phenol.
After the stages A and B, a cyanamide with m.p. 151"C is obtained with yield 92% This compound provides by methylation, carried out as in Example 1, a monomethyletherwith a conversion of 55% and a yield of 78% on the converted product. The condensation with 4-methyl-5-(2-aminomethyl)-thiomethyl-imidazole, carried out as in example 1, but in isopropyl alcohol, provides Cimetidine with a conversion of 65% and a yield of 82% on the converted product.
Example 4
The procedure of Example 1 was repeated, using 2,4-xylenol instead of phenol. After the stages A and B, a cyanamide with m.p. 1420C is obtained with a yield of 94%. The methylation, carried our as in Example 1, provides a conversion of 60% and a yield of 80% on the converted product. The condensation with 4-methyl-5-(2-aminoethythiomethyl-imidazole, carried out as in Example 3, provides Cimetidine with a conversion of 60% and a yield of 85% on the converted product.
Example 5
The procedure of Example 1 was repeated, using a-naphtol instead of phenol.
After the stages A and B, a cyanamide with m.p. 1 850C is obtained with a yield of 96%. The methylation, carried out in Example 1, provides a conversion of 58% and a yield of 85% on the converted product. The condensation with the imidazolic amine, carried out in Example 3, provides cimetidine with a conversion of 64% and a yield of 87% on the converted product.
Claims (17)
1. A process for the preparation of cimetidine of the formula:
comprising reaction of 4-methyl-5-[(2-aminoethyl)-thiomethyl].imidazole of the general formula:
with a compound of the general formula:
(where Ar represents an aliphatic radical with 3-6 carbon atoms or an aromatic radical which is either unsubstituted or which is substituted with one or more alkyl groups each with 1-3 carbon atoms).
2. A process according to claim 1, in which the reaction is effected in an organic solvent at the reflux temperature of the mixture.
3. A process according to claim 1 or claim 2, in which the compound of the general formula Ill is obtained by first methylating the corresponding compound of the general formula:
(where Ar is as defined in claim 1) by reaction with a methylating agent.
4. A process according to claim 3, in which the methylating reagent is of the formula CH3Y, where Y represents a halogen atom, or a sulphate, sulphonic or phosphoric radical.
5. A process according to claim 3 or claim 4, in which the methylating agent is used in an amount of 50 to 100% of the stoichiometric quantity.
6. A process according to any of claims 3 to 5, in which the compound of the general formula IV is obtained by first condensing cyanamide with an isocyanate of the general formula:
Ar-OCN (V) (where Ar is as defined in claim 1).
7. A process according to claim 6, in which the condensation reaction is effected in the presence of a catalytic amount of a strong base.
8. A process according to claim 7, in which the strong base is a tertiary amine.
9. A process according to any of claims 6 to 8, in which the isocyanate of formula V is obtained by first reacting the corresponding compound ArOH (where Ar is as defined in claim 1) with a cyanogen halide.
10. A process according to claim 9, in which the cyanogen halide is the bromide or chloride.
11. A process according to claim 9 or claim 10, in which the reaction is effected in an organic solvent in the presence of an organic or inorganic base.
12. A process according to claim 11, in which the base is a tertiary amine.
13. A process according to any of claims 9 to 12, in which the reaction is effected at 0-20"C.
14. A process according to any of claims 9 to 13, in which free hydroxy compound of formula ArOH (where Ar is as defined in claim 1) regenerated in the reaction of the compounds of formulae II and Ill is recycled to the reaction with a cyanogen halide.
15. A process according to any of claims 9 to 14, in which the compound ArOH is phenol, a cresol, a xylenol or a naphthol.
16. A process for the preparation of cimetidine of the formula:
in which an isocyanate of the formula ArOCN (where Ar represents an aliphatic radical with 3-6 carbon atoms or an aromatic radical which is either unsubstituted or is substituted with one or more alkyl groups with 1-3 carbon atoms) is reacted with cyanamide to form a compound of the general formula
(where Ar is as defined above); which is then methylated and condensed with a compound of the formula
17. A process according to claim 16, comprising the following reaction sequence: (A) ArOH+XCN < ArOCN + Hx in which Ar is as defined above and X=CI or Br
in which Ar is as specified above.
in which Ar is as specified above and Y is an halogen, sulphate, sulphonic or phosphoric radical
in which Ar is as specified above.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB08137175A GB2111044B (en) | 1981-12-09 | 1981-12-09 | Process for the production of cimetidine |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB08137175A GB2111044B (en) | 1981-12-09 | 1981-12-09 | Process for the production of cimetidine |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB2111044A true GB2111044A (en) | 1983-06-29 |
| GB2111044B GB2111044B (en) | 1986-11-19 |
Family
ID=10526498
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB08137175A Expired GB2111044B (en) | 1981-12-09 | 1981-12-09 | Process for the production of cimetidine |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB2111044B (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4739077A (en) * | 1985-01-31 | 1988-04-19 | Smith Kline & French Laboratories Limited | Process for preparing an aziridine derivative |
| US4777260A (en) * | 1985-12-18 | 1988-10-11 | Eli Lilly And Company | Synthesis of nizatidine intermediate |
-
1981
- 1981-12-09 GB GB08137175A patent/GB2111044B/en not_active Expired
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4739077A (en) * | 1985-01-31 | 1988-04-19 | Smith Kline & French Laboratories Limited | Process for preparing an aziridine derivative |
| US4777260A (en) * | 1985-12-18 | 1988-10-11 | Eli Lilly And Company | Synthesis of nizatidine intermediate |
Also Published As
| Publication number | Publication date |
|---|---|
| GB2111044B (en) | 1986-11-19 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4413129A (en) | Process for preparing the H2 -receptor antagonist cimetidine | |
| US2184279A (en) | Amino-aliphatic sulphonamides and process for preparing them | |
| CZ280732B6 (en) | Process for separating isocyanic acid from a mixture of said acid with ammonia | |
| US4131617A (en) | Preparation of new isobutylramide derivatives | |
| SU1072800A3 (en) | Process for preparing 2-mercaptoethylamine hydrogalogenides and its modification | |
| US4093667A (en) | Preparation of 4-n-hexylresorcinol | |
| GB2111044A (en) | Process for the production of cimetidine | |
| US5212318A (en) | Preparation of omega-substituted alkanamide | |
| US5696290A (en) | Synthesis of penta-substituted guanidines | |
| US3920656A (en) | Method of making barbituric acid compounds | |
| US4389349A (en) | Process for preparing of N-phosphenomethyl glycine | |
| KR870002019B1 (en) | Process for preparation of amine derivatives | |
| HU190367B (en) | Process for producing 1-carbamoyl-1,3-bracket-3,5-dichloro-phenyl-bracket closed-hidanthoines and the intermediate 1-chloro-carbonyl-3-bracket-3,5-dichloro-phenyl-bracket closed-hidanthoine | |
| US4188343A (en) | Process for preparing anthranylaldehyde derivatives | |
| JPS6136270A (en) | Manufacture of 2_alkyl_4,5_dihydroxymethylimidazole | |
| US5220041A (en) | Sulfonate ester | |
| KR840001563B1 (en) | Process for preparing 1-carbymayl-3-(3,5-dichlorophenyl)-hydantoins | |
| JP2659587B2 (en) | 4-aziridinyl pyrimidine derivatives and their production | |
| US2899429A (en) | Nitroethylenes | |
| US4418210A (en) | Process for producing asymmetrical thioureas | |
| EP0119799B1 (en) | Process for preparing dialkyl propanediimidate dihydrohalides | |
| JPS6132305B2 (en) | ||
| KR800000717B1 (en) | Method for preparing N ”-cyano-N-methyl-N '-[2- (5-methylimidazol-4-yl) -methylthio] ethylguanidine | |
| DE3148103A1 (en) | Process for the preparation of cimetidine | |
| US5550288A (en) | Process for the preparation of α-aminoacylanilides |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PCNP | Patent ceased through non-payment of renewal fee |