Patent ID: 6359164
Filing Date: 2002-03-19
Classification: C07C

Abstract:
A process for the preparation of a compound of formula (III); wherein:R1 is selected from: C1-8 alkyl substituted with 0-3 R4, C3-10 cycloalkyl substituted with 0-2 R5, and aryl substituted with 0-2 R6; R4, at each occurrence, is selected from methyl, ethyl, propyl, butyl, OR7, NR7R7a, phenyl, and cyclopropyl; R5, at each occurrence, is selected from D, methyl, ethyl, propyl, methoxy, ethoxy, and propoxy; R6, at each occurrence, is selected from methyl, ethyl, propyl, methoxy, ethoxy, propoxy, F, Cl, B, I, CN, and NR7R7a; R7 and R7a are independently selected from methyl, ethyl, propyl, and butyl; said process comprising:(1a) reacting an aldehyde of formula R1â€”CHO with trichloroacetic acid or tribromoacetic acid, in the presence of a base catalyst; (1b) reacting the solution of (1a) with zinc in the presence of an organic acid having one to six carbon atoms to form a compound of formula (II); â€ƒwherein R2 is Cl or Br; and (2) reacting a compound of formula (II) with a strong base to form a compound of formula (III).