Patent ID: 8501993

Claim:
A process for the preparation of a compound of formula (II) R5, R6, R7 and R8 are each independently hydrogen or alkyl; R9 is hydrogen, optionally substituted alkyl, optionally substituted alkenyl or optionally substituted alkynyl; R10 is optionally substituted aryl, optionally substituted heteroaryl; X is H, a protecting group, or a group of the formula (III) wherein R1 is hydrogen, alkyl, cycloalkyl or optionally substituted aryl; R2 and R3 are each independently hydrogen or alkyl; Y is R4, H or a protecting group; R4 is alkyl, alkenyl or alkynyl; z is optionally substituted alkynyloxy; comprising reacting a carboxylic acid of formula (IV) with an amine of formula (V) wherein the reaction is conducted in the presence of an arylboronic acid catalyst or boric acid.