Potassium Hydroxide → Tert-butyl (2s)-2-[(diphenylmethylene)amino]-3-[4-(trifluoromethoxy)phenyl]propanoate

Participants

Reaction Steps

1-(Bromomethyl)-4-(trifluoromethoxy)benzene (28.1 g, 0.110 mol) and 50% potassium hydroxide (225 mL, 2.00 mol) were added to a toluene (1 L) suspension of tert-butyl [(diphenylmethylene)amino]acetate (29.5 g, 0.10 mol) and N-(9-anthracenylmethyl)cinchonidinium chloride (5.79 g, 0.01 mol) under ice-cooling with stirring. The mixture was vigorously stirred at the same temperature for 3.25 hours and then separated into an organic layer and an aqueous layer. The aqueous layer was extracted with ethyl acetate (200 mL), and the organic layers were combined, washed with saturated brine, and dried over anhydrous magnesium sulfate. The solvent was evaporated, and the obtained residue was purified by silica gel column chromatography (n-hexane:ethyl acetate, 20:1, 15:1, and 10:1, V/V) to give 41.2 g of the title compound (mixture of a yellow oil and a yellow solid, yield: 88%, optical purity: 88%).

Provenance & Evidence