Patent ID: 7485731

Claim:
A method for preparing enantiomerically pure 4-pyrrolidino derivatives of the formula I: said method comprising reacting a compound of formula (II): with (S)-N-(5-oxo-tetrahydro-furan-3-yl)-acetamide to obtain a compound of formula (III): and then cyclizing the compound of formula (III) to obtain the compound of formula (I); wherein R 1 is halogen, halogen-(C 1 -C 6 )-alkyl, cyano, (C 1 -C 6 )-alkoxy or halogen-(C 1 -C 6 )-alkoxy; R 21 , R 22 , R 23 and R 24 are each independently selected from the group consisting of hydrogen and halogen; and n is 0, 1, 2 or 3.