摘要:
A process for the preparation of 5-(2,4-difluorophenyl)-salicylic acid comprising the reaction of an organometallic derivative with a suitable substituted benzene in the presence of a transition-metal based catalyst is described.
摘要:
Process for the preparation of (2S,3S)-2,3-dihydro-3-hydroxy-2-(4-methoxyphenyl)-1,5-benzothiazepin-4(5H)-one of formula ##STR1## by direct cyclization of the compound of the formula ##STR2## with a catalytic amount of phosphonic acid.
摘要:
A process for the preparation of intermediates useful for the synthesis of Diltiazem consisting in the racemization of (--)-cis-2,3-dihydro-3-hydroxy-2-(4-methoxyphenyl)-1,5-benzothiazepin-4(5H)-one is described.
摘要:
This invention relates to a process for the preparation of 4-[2-(dimethylamino)-ethoxy]-2-methyl-5-(1-methylethyl)-phenol esters (I) and their salts with organic and inorganic acids comprising the reaction of thymol with a salt of an 1-halo-dimethylaminoethane to obtain ethylamine-N,N-dimethyl-2-(thymyloxy) (II), the subsequent reaction of (II) with an acylating agent according to the Friedel and Kraft reaction to obtain 4-[2-(dimethylamino)-ethoxy]-2-methyl-5-(1-methylethyl)-1-acyl-benzene (III) and the oxidation of (III) to obtain the products (I) which, if desired, may be transformed in their salts with organic or inorganic acids.This process allows to obtain the products (I) in high quality and quantity without isolating any intermediate product.
摘要:
Esters of arylacetic acids, more particularly lower alcohol esters of arylacetic acids, including those substituted on the methylene group, are prepared by rearrangement of the corresponding alpha-halo-alkylarylketones with Ag compounds in lower alcohols and in an acid medium. From the alkyl esters so prepared, their respective free acids can be obtained, if desired, by various means such as hydrolysis or the shift with mineral acids of the alkaline salts prepared by reaction with alkali, etc.
摘要:
The invention relates to a new process for the production and/or purification of the salt of the compound (S)-2-[4-(2-fluorobenzyloxy) benzylamino]propanamide, i.e. ralfinamide, or the respective R-enantiomer, with methane sulfonic acid in high yields and very high enantiomeric and chemical purity in the form of the crystalline anhydrous polymorph identified as form A, wherein said salt is substantially free from impurities having genotoxic effect, such as (C1-C5)alkanylmethanesulfonates, and residual solvents known as potential precursors thereof, such as (C1-C5)alkanols or esters thereof with lower alkanoic acids.
摘要:
Intermediates for transforming (2S,3S)-2-amino-3-phenyl-1,3-propanediols into their (2R,3R)-enantiomers are described. The final compounds are useful intermediates for the synthesis of antibiotics like Chloramphenicol, Thiamphenicol and Florfenicol.
摘要:
A process for the preparation of 4-(2,4-difluorophenyl)-phenyl 4-nitro-benzoate, an intermediate for the preparation of 5-(2,4-difluorophenyl)-salicylic acid, which is a drug known with the international non-proprietary name Diflunisal, is described.
摘要:
A four step process for transforming (2S,3S)-2-amino-3-phenyl-1,3-propanediols into their (2R,3R)-enantiomers is described. The final compounds are useful intermediates for the synthesis of antibiotics like Chloramphenicol, Thiamphenicol and Florfenicol. The starting products generally are discard products in the synthesis of said antibiotics.
摘要:
A process for the preparation of 4-(2,4-difluorophenyl)-phenyl 4-nitro-benzoate, an intermediate for the preparation of 5-(2,4-difluorophenyl)-salicylic acid, which is a drug known with the international non-proprietary name Diflunisal, is described.