A Facile Synthesis of a Sterically Congested Amide: A Convenient Method of Steroidal 17β-Amide Synthesis from 17β-Carboxylic Acid and a Hindered Amine with 2,4,6-Triisopropylbenzenesulfonyl Chloride as a Condensing Reagent

Steroidal 17β-amides 2, 4, 6 were synthesized from the 17β-carboxylic acids 1, 3, 5 and sterically hindered amine in 88-100% yields using 2,4,6-triisopropylbenzenesulfonyl chloride as a condensing reagent. This method was successfully applied to the synthesis of sterically congested simple amide 8.