Patent ID: 7994341

Claim:
A process for the preparation of a compound of formula I: wherein R 1 and R 2 are each independently hydrogen or C 1 -C 5 alkyl, and R 3 is CF 3 or CF 2 H, which comprises: a) reacting a compound of formula II: wherein R 1 and R 2 are as defined for formula I, with at least one reducing agent to form a compound of formula III: wherein R 1 and R 2 are as defined for formula I; (b) reacting the compound of formula III with at least one reducing agent to form a compound of formula IV: wherein R 1 and R 2 are as defined for formula I; and (c) converting the compound of formula IV into the compound of formula I by reaction with a compound of formula V: wherein Q is chlorine, fluorine, bromine, iodine, hydroxy or C 1 -C 6 alkoxy, and R 3 is as defined for formula I.