3-[Isopropyl-(4-oxo-cyclohexanecarbonyl)-amino]-5-phenyl-thiophene-2-carboxylic acid methyl ester → 3-[Isopropyl-(4-methylene-cyclohexanecarbonyl)-amino]-5-phenyl-thiophene-2-carboxylic acid methyl ester

Participants

Reaction Steps

Butyllithium (2.5 M, 0.9 mL, 2.280 mmol) was added to a cold solution (−78° C.) of methyltriphenylphosphonium bromide (939 g, 2.630 mmol) in THF (10 mL). The reaction mixture was stirred at room temperature for 1 h and then 3-[Isopropyl-(4-oxo-cyclohexanecarbonyl)-amino]-5-phenyl-thiophene-2-carboxylic acid methyl ester. (700 mg, 1.754) in THF (5 mL) was added at −78° C. The reaction mixture was allowed to stir at room temperature for 12 h. The reaction was quenched by adding saturated solution of NH4Cl and diluted with ethyl acetate. The organic layer was separated, dried (Na2SO4) and concentrated. The residue was purified by silica gel column chromatography using ethyl acetate: hexane (1:4) to obtain 3-[Isopropyl-(4-methylene-cyclohexanecarbonyl)-amino]-5-phenyl-thiophene-2-carboxylic acid methyl ester (300 mg, 43%) as a solid. 1H NMR (CDCl3, 400 MHz): δ7.63 (d, 2H), 7.50-7.38 (m, 3H), 7.12 (s, 1H), 4.99 (m, 1H), 4.55 (d, 2H), 3.85 (s, 3H), 2.25 (m, 3H), 1.83-1.63 (m, 5H), 1.50 (m, 1H), 1.25 (d, 3H), 0.99 (d, 3H).

Provenance & Evidence