6-Chloronicotinic acid → HCID 12953061, compound

Participants

Reaction Steps

A mixture of 18.5 g (0.1 mol) of 4-amino-2,5-dimethyl-3-thiophenecarboxylic acid, methyl ester and 15.76 g (0.1 mol) of 6-chloro-3-pyridinecarboxylic acid (Aldrich Chemical Company) is heated in a wax bath at 168°-186° C. for one hundred ten minutes and then at 185°-186° C. for ninety minutes under nitrogen. The mixture is cooled, suspended in hot methanol, cooled and 4.2 g of crude product is collected. This material is dissolved in hot pyridine, activated charcoal (Darco-G60, Matheson, Coleman and Bell) is added and the hot suspension is filtered through Supercell Hyflo® (Johns-Manville). The filtrate is cooled to give 1.75 g of 1,3-dimethyl-10-oxo-10H-pyrido[1,2-a]thieno[3,4-d]pyrimidine-7-carboxylic acid; mp 336° C. (dec) after recrystallization from pyridine.

Provenance & Evidence