摘要:
The invention relates to novel compound of formula (IV), which is an organic acid salt of N-[(2′-cyanobiphenyl-4-yl)methyl]-(L)-valine ester. This compound is an useful intermediate for process of preparation of Valsartan of formula (I), chemically known as (S)—N-(1-Carboxy-2-methylprop-1-yl)-N-pentanoyl-N-[2′-(1H-tetrazol-5-yl)biphenyl-4-ylmethyl]amine. This invention also relates to a process for preparing Valsartan using novel intermediate of formula (IV).
摘要:
The present invention provides a process for the preparation of 6-O-methylerythromycin A Form II comprising treating 6-O-methylerythromycin A with organic acid selected form trifluoroacetic acid, para-toluene sulphonic acid, oxalic acid or acetic acid and converting it into an organic salt of 6-O-methylerythromycin A, which can be neutralized by base to give 6-O-methylerythromycin A Form II.
摘要:
The present invention relates to an improved process for the preparation of (E)-N,N-diethyl-2-cyano-3-(3,4-dihydroxy-5-nitrophenyl)acrylamide formula (I) comprising steps of, (a) condensation of 3,4-dihydroxy-5-nitrobenzaldehyde of formula (II) with N,N-diethylcyanoacetamide of formula (III) in the presence of a catalyst and optionally in the presence of phase transfer catalyst in a solvent selected from the group comprising of ethylacetate, acetonitrile, hydrocarbon such as toluene, xylene and like or mixture thereof to give mixture of (E) and (Z)-isomer of N,N-diethyl-2-cyano-3-(3,4-dihydroxy-5-nitrophenyl)acrylamide of formula (IV). b) treating an isomeric mixture of (E) and (Z)-isomer of N,N-diethyl-2-cyano-3-(3,4-dihydroxy-5-nitrophenyl)acrylamide of formula (IV) obtained in step (a) with a halogen in catalytic amounts, in a solvent to give (E)-N,N-diethyl-2-cyano-3-(3,4-dihydroxy-5-nitrophenyl)acrylamide formula (I).