Trifluoroacetic acid → Methyl 2-(4-fluoro-3-nitrophenyl)-3,3-dimethyl-1,2,3,4-tetrahydroquinoline-6-carboxylate

Participants

Reaction Steps

To an ice-cooled mixture of methyl 2-(4-fluoro-3-nitrophenyl)-4-hydroxy-3,3-dimethyl-1,2,3,4-tetrahydroquinoline-6-carboxylate (3.39 g, 9.06 mmol) and triethylsilane (3.06 g, 26.3 mmol) in dichloromethane (180 mL) was added a solution of trifluoroacetic acid (4.24 g, 37.1 mmol) in dichloromethane (90 mL) dropwise during 3 hours. After addition, ice-bath was removed and the reaction mixture was stirred at room temperature for 44 hours. Solid sodium carbonate was added and stirred for 15 minutes, filtered, and concentrated. The oil residue was purified by column (silica gel, petroleum ether/ethyl acetate=10:1 to 1:1 due to bad solubility) to afford methyl 2-(4-fluoro-3-nitrophenyl)-3,3-dimethyl-1,2,3,4-tetrahydroquinoline-6-carboxylate 2.44 mg (75%) as a yellow solid.

Provenance & Evidence