Processes for the preparation of simvastatin

摘要

Improved processes for the preparation of 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) inhibitors, e.g., simvastatin, and their intermediates are provided. In one embodiment, a process for the preparation of a carboxylic acid amine salt of formula I is provided wherein R¹ and R² are as defined herein, the process comprising reacting lovastatin with an amine of formula III: in an aqueous medium to provide the carboxylic acid amine salt of formula I. The process further includes the steps of lithiating the carboxylic acid amine salt of formula I to form the corresponding 2,2-dimethylbutyrate intermediate of formula IIa lactonizing the 2,2-dimethylbutyrate intermediate (IIa) to provide simvastatin and pharmaceutically acceptable salts thereof. Also provided is an improved process for lactonization of the intermediates herein using peptide coupling reagents.