One-pot synthesis of amides from carboxylic acids activated using thionyl chloride

A one-pot synthesis of secondary and tertiary amides from carboxylic acids and amines by using SOCl2 hasbeen developed. Also when sterically hindered amines were used as the starting materials, excellent yieldsof the corresponding amides were obtained. The amidation of N-protected a-amino acids with secondaryamines proceeds effectively with good yields. The process works well also in the presence of acid sensitivegroups and occurs with almost complete retention of stereochemical integrity of chiral substrates. Thisprotocol could be extended to industrial large-scale production processes.