Patent ID: 6875885

Claim:
A process for producing compounds of formula (VIIa) and (VIIb) wherein X is Cl or Br; Y and Y 1 are independently Cl or Br; and Z is Cl, Br or a haloalkyl group which process comprises a) reacting a compound of formula (VII) wherein X, Y, Y 1 arid Z are as defined for compounds (VIIa) and (VIIb) with a substantially optically pure chiral amine selected from R(+)-alpha methyl benzylamine and (1S,2R)-1-amino-2-indanol in a solvent to form a diastereoisomeric salt; b) separating the diastereomeric salt of each enantiomer; c) converting the diastereomeric salt of each enantiomer separately to compounds of formulae (VIIa) and (VIIb) respectively by acid or base hydrolysis.