SUBSTANTIALLY PURE ROSIGLITAZONE HYDROGEN SULFATE

摘要

Provided herein are impurities of rosiglitazone hydrogen sulfate, 4-[2-(N-methyl-2-(N- pyridinyl)amino)ethoxy]bromobenzene (bromo impurity) and 5-[[4-[2-[methyl-(2-pyridinyl- N-oxide)amino]ethoxy]phenyl]methyl]-2,4-thiazolidinedione (N-oxide impurity), and processes for preparing and isolating thereof. Provided further herein is a highly pure rosiglitazone hydrogen sulfate substantially free of bromo and N-oxide impurities, process for the preparation thereof, and pharmaceutical compositions comprising highly pure rosiglitazone hydrogen sulfate substantially free of bromo and N-oxide impurities.