Triethylamine → HCID 66664758, compound

Participants

Reaction Steps

Ethyl malonyl chloride (4.29 g, 28 mmol) was added to a solution of methyl 3-amino-4-methylthiophene-2-carboxylate (4 g, 23 mmol) and triethylamine (4.2 mL, 30 mmol) in dichloromethane (50 mL) and the resulting mixture was stirred for 30 minutes. The reaction mixture was diluted with dichloromethane, washed with water and brine, dried over anhydrous sodium sulfate, filtered and evaporated under reduced pressure. To the oily residue was added a freshly prepared ethanolic solution of sodium ethoxyde (0.5 g in 25 mL of EtOH) and the reaction mixture was heated at reflux overnight. The solvent was evaporated under reduced pressure and water (50 mL) was added to the residue, followed by sodium hydroxide (1.5 g). The resulting mixture was heated at reflux overnight, then was cooled and acidified by addition of an aqueous solution of hydrochloric acid (6 M). The solid formed was collected by filtration, washed with water and dried under reduced pressure to afford 2.0 g of 3-methyl-4H-thieno[3,2-b]pyridine-5,7-dione.

Provenance & Evidence