Hydrochloric Acid → 3-{4-[3-(5,5-Dimethyl-3-trifluoromethyl-4,5,6,7-tetrahydro-benzo[c]thiophen-1-yl)-3-oxo-propenyl]-2-ethyl-6-methyl-phenyl}-acrylic acid ethyl ester

Participants

Reaction Conditions

Reaction Steps

A solution of 1-(5,5-dimethyl-3-trifluoromethyl-4,5,6,7-tetrahydro-benzo[c]thiophen-1-yl)-ethanone (500 mg, 1.81 mmol) and 3-(2-ethyl-4-formyl-6-methyl-phenyl)-acrylic acid (395 mg, 1.81 mmol) in ethanol (25 mL) is treated with 5 N HCl in isopropanol (15 mL). The orange brown reaction mixture is stirred at 65° C. for 64 h. The mixture is diluted with sat. aq. NaHCO3 solution and extracted twice with EA. The organic extracts are washed with sat. NaHCO3 solution, dried over MgSO4, filtered and the solvent of the filtrate is evaporated. The crude product is purified by CC on silica gel eluting with heptane:EA 9:1 to give 3-{4-[3-(5,5-dimethyl-3-trifluoromethyl-4,5,6,7-tetrahydro-benzo[c]thiophen-1-yl)-3-oxo-propenyl]-2-ethyl-6-methyl-phenyl}-acrylic acid ethyl ester (634 mg, contains traces of the corresponding isopropyl ester) as a colourless oil; LC-MS: tR=1.32 min, [M+1]=505.04.

Provenance & Evidence