Patent ID: 6211413
Filing Date: 2001-04-03
Classification: C07C

Abstract:
A process for the preparation of a compound of formula I ##STR7##wherein:X is H or F,Y is CF.sub.3 or F andR.sub.1 is C.sub.1 -C.sub.2 alkyl; in which process ##STR8##(1) a compound of formula II, wherein X and Y are as defined for formula I, is reacted with (i) an organic nitrite in an organic solvent; or (ii) nitrous acid or a salt thereof in aqueous solution, in the presence of an acid selected from the group consisting of sulfuric acid and nitrosulfuric acid;(2) the resulting diazonium compound of formula III is reacted with an aldoxime of formula VR.sub.1 --CH.dbd.NOH (V)wherein R.sub.1 is as defined for formula I, in the presence of CuSO.sub.4 and a hydrophobic solvent; and(3) the resulting oxime of formula IV is hydrolyzed with aqueous acid to the compound of formula I.