Patent ID: 8058454

Claim:
A process for preparing a compound of formula (I): or a pharmaceutically acceptable salt thereof, wherein R 1 is selected from the group consisting of â€”CONH 2 and â€”CN; R 2 is selected from the group consisting of â€”CH 2 â€” or â€”Câ•O; R 3 and R 4 are each hydrogen, or taken together form a double bond between the carbon atoms to which they are bonded, comprising reacting a compound of formula (II): or a salt or solvate thereof, wherein R 1 is defined as above, with a compound of formula (III): or solvate thereof, wherein R 2 , R 3 , and R 4 are defined as above; and Z is a leaving group, in the presence of an organic solvent, a phase-transfer catalyst, a base, and optionally water.