Patent ID: 7479556

Claim:
A process for preparing a compound of formula (VI): in which: X is Cl or Br; R 4 is H and R 3 is selected from the group consisting of comprising: (1) reacting a compound of formula (III) in which R 2 is selected from the group consisting of with a trialkylsilyl reactant to form a trialkylsilylester intermediate, (2) reacting said trialkylsilylester intermediate with a compound of formula (V), in which X is Cl or Br, Y is Cl or O—CH═N + (CH 3 ) 2 Cl − , to obtain a compound of formula (VI′) in which: X is Cl or Br; R 4 is trialkylsilyl and R 3 is selected from the group consisting of and (3) hydrolyzing the compound of formula (VI′) in wet isopropanol to obtain the compound of formula (VI).