Patent ID: 7652134

Claim:
A method for preparing a compound having formula 2, comprising contacting an ester having formula 4, an amine with formula NHR 1 R 2, and a Lewis acid having formula ML n , wherein L is a halogen atom or an alkyl group, n is 3-5, and M is a group III elemental atom, a group IV elemental atom, As, Sb, vanadium, or Fe, wherein A, V, and X are independently H, halo, azido, R 2, CH 2 R 2, SR 2, OR 2 or NR 1 R 2 ; wherein in NR 1 R 2 , R 1 and R 2 may form an optionally substituted ring; Z is O, S, or NR 1 ; Z 5 , Z 6 , Z 7 , and Z 8 are C; each R 1 is H or a C 1-6 alkyl; each R 2 is a C 1-10 alkyl or C 2-10 alkenyl optionally containing one or more non-adjacent heteroatoms selected from N, O, and S, and optionally substituted with a carbocyclic or heterocyclic ring; or R 2 is an optionally substituted carbocyclic ring, heterocyclic ring, aryl or heteroaryl; each W is an optionally substituted aryl or heteroaryl, which may be monocyclic, or fused with a single or multiple ring and optionally containing a heteroatom; and each R 5 is a substituent at any position on W; and is H, OR 2 , NR 1 R 2 , C 1-6 alkyl, C 2-6 alkenyl, each optionally substituted by halo, C═O or one or more heteroatoms; or two adjacent R 5 are linked to obtain a 5-6 substituted or unsubstituted carbocyclic or heterocyclic ring, optionally fused to an additional substituted or unsubstituted carbocyclic or heterocyclic ring.