Ammonium Chloride → Cyclohexyl[3-methyl-6-(trifluoromethyl)thieno[3,2-b]pyridin-2-yl]methanone

Participants

Reaction Steps

To a solution (15 mL) of 3-methyl-6-(trifluoromethyl)thieno[3,2-b]pyridine-2-carbaldehyde (1.44 g) synthesized above in tetrahydrofuran was added 1.0M solution (8.81 mL) of cyclohexylmagnesium bromide in tetrahydrofuran at 0° C., and the mixture was stirred for 1 hr under argon atmosphere. Saturated aqueous ammonium chloride solution was added to quench the reaction, and the reaction mixture was extracted with ethyl acetate. The extract was washed with saturated brine, dried over magnesium sulfate, and concentrated under reduced pressure. The residue was purified by silica gel column chromatography (10-50% ethyl acetate/hexane) to give a yellow oil. To a mixture of the obtained oil, 4-methylmorpholine N-oxide (817 mg) and acetonitrile (20 mL) was added tetrapropylammonium perruthenate (108 mg), and the mixture was stirred at room temperature for 1 hr, and concentrated under reduced pressure. The residue was purified by silica gel column chromatography (0-10% ethyl acetate/hexane) to give the title object compound (805 mg, 42%) as a yellow solid.

Provenance & Evidence