Patent ID: 7138527

Claim:
A process for preparing a compound of formula (1) comprising coupling an acid of formula (2): with an amine of formula (3): wherein n is 0, 1, 2, 3 or 4; R 1 and R 2 are each independently selected from hydrogen and (C 1 –C 4 )alkyl; R 3 is selected from the group consisting of hydrogen and (C 1 –C 6 )alkyl optionally substituted by a hydroxy; and R 4 , R 5 , R 6 , R 7 and R 8 are each independently selected from the group consisting of hydrogen, hydroxy, (C 1 –C 6 )alkyl, (C 1 –C 6 )alkoxy, benzyloxy, hydroxy(C 1 –C 6 )alkyl, thio(C 1 –C 6 )alkyl, halo and trifluoromethyl.