Dimethylformamide → 1,3-Dibenzyl (3RS,4SR)-3-[2-(tert-butoxy)-2-oxoethyl]-4-methylpyrrolidine-1,3-dicarboxylate

Participants

Reaction Conditions

Reaction Steps

Benzyl bromide (4.48 ml, 37.7 mmol) was added to a mixture of (3RS,4SR)-1-[(benzyloxy)carbonyl]-3-[2-(tert-butoxy)-2-oxoethyl]-4-methylpyrrolidine-3-carboxylic acid obtained in Reference Example 1b (14.5 g, 38.5 mmol), potassium carbonate (10.6 g, 77 mmol) and N,N-dimethylformamide (50 ml) with stirring under ice-cooling (internal temperature: 3 to 7° C.), and the mixture was stirred for one hour, returned to mom temperature and stirred overnight. Water was added to the reaction liquid, which was extracted with ethyl acetate three times. The organic layers were combined, sequentially washed with a saturated aqueous ammonium chloride solution (five times), water (twice) and brine, and then dried over sodium sulfate, filtered and concentrated to give the title compound (17.67 g, yield: 98.2%).

Provenance & Evidence