- PROCESS FOR THE PREPARATION OF VERAPAMIL
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The present invention relates to a process for the preparation of α-[3-[[2-(3,4-dimethoxyphenyl)ethyl]methylamino]propyl]-3,4-dimethoxy-α-(1-methylethyl), monohydrochloride (verapamil hydrochloride, a compound of formula I), the process comprising treating verapamil (a compound of formula IA) with alkyl haloformate and/or sodium dihydrogen phosphate, followed by treating with hydrochloric acid to get verapamil hydrochloride in good yield and good purity.
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Paragraph 0067
(2021/12/31)
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- A PROCESS FOR THE PREPARATION OF VERAPAMIL HYDROCHLORIDE
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The present invention relates to a process for the preparation of 5-(3,4-dimethoxyphenylethyl) methyl-amino-2-(3,4-dimethoxyphenyl)-2-isopropyl valeronitrile, which is known as Verapamil. The present invention also relates to a process for improving the purity of verapamil and therefore of its hydrochloride represented as the compound of formula I, by efficient removal of the impurities formed, affording a product of purity greater than 99 %. The process of the present invention is simple, efficient, cost-effective and industrially feasible.
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Page/Page column 11
(2016/12/01)
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- A process for the resolution of racemic verapamil
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A new process is described for the resolution of racemic verapamil, which allows the desired enantiomer to be obtained in high yields and with high enantiomeric purity. The process uses optically active 2,3-bis[(2-fluorobenzoyl)oxy]butanedioic acid as the
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Page/Page column 5
(2009/01/24)
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- PROCESS FOR PREPARING N-METHYL-3, 4-DIMETHOXYPHENYLETHYLAMINE
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Provided are intermediates useful for the preparation of verapamil and methods for their preparation.
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Page/Page column 6
(2009/07/17)
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- Process for the resolution of racemic verapamil
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A new process is described for the resolution of racemic verapamil, which allows the desired enantiomer to be obtained in high yields and with high enantiomeric purity. The process uses optically active 2,3-bis[(2-fluorobenzoyl)oxy]butanedioic acid as the resolving agent, and a water/dimethylformamide or water/acetonitrile or water/methanol mixture, as the reaction solvent.
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Page/Page column 3
(2009/01/20)
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- A scaleable route to the pure enantiomers of verapamil
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A versatile route to single enantiomer verapamil from readily available raw materials is described. The key intermediate, 4-cyano-4-(3,4-dimethoxyphenyl)-5-methyl hexanoic acid (verapamilic acid), was resolved efficiently with α-methyl benzylamine. Stereochemical integrity at the quaternary carbon centre was preserved through subsequent steps to give either (R)-or (S)-verapamil in good overall yield. This sequence incorporated a selective borane-mediated reduction of a tertiary amide. Process scale-up to the pilot plant has been demonstrated successfully for the resolution step.
- Bannister, Robin M.,Brookes, Michael H.,Evans, Graham R.,Katz, Ruth B.,Tyrrell, Nicholas D.
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p. 467 - 472
(2013/08/07)
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- Compound and process
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A process for the preparation of a compound of formula (VI), optionally in enantiomerically-enriched form (R or S), comprises chemoselective reduction of a novel compound of formula (V), wherein Ar1 and Ar2 are independently selected from optionally-substituted aromatic or heteroaromatic groups having upto 20 C atoms, Ak is C1-20 alkyl, and R is H or C1-20 alkyl. STR1
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- Preparation of phenylacetonitriles carrying basic substituents
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A process for the preparation of phenylacetonitriles, carrying basic substituents, of the formula I STR1 where R1, R2, R3, R4, R5, R6, R7 and R8 have the meanings given in the description, by reacting an aldehyde of the formula II STR2 with an amine of the formula III STR3
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