Sodium triacetoxyborohydride → (R)-tert-butyl 2-((6-(methoxycarbonyl)-2,3-dihydro-1H-inden-1-ylamino)methyl)-1H-pyrrole-1-carboxylate

Participants

Reaction Conditions

Reaction Steps

A solution of (3R)-3-amino-2,3-dihydro-1H-indene-5-carboxylic acid methyl ester (A-03) (361 mg, 1.88 mmol, 1 eq.) in methylene chloride (3 ml) was added to a solution of tert-butyl 2-formyl-5-methyl-1H-pyrrole-1-carboxylate (434 mg, 2.08 mmol, 1.1 eq.) in dry methylene chloride (17 ml) at 0° C. and the resulting reaction mixture was stirred at 25° C. for 2 h. The reaction mixture was cooled to 0° C. and then Na(OAc)3BH (1.2 g, 5.66 mmol, 3 eq.) was added portionwise and it was stirred at 25° C. for 14 h. The reaction mixture was diluted with methylene chloride (200 ml) and washed with saturated sodium bicarbonate (50 ml), water (2×50 ml) and brine (50 ml), and dried over sodium sulfate. The solvent was evaporated under reduced pressure and the residue was purified by column chromatography (silica gel; 5% EtOAc/hexanes) to give the desired product as a light yellow oil. Yield: 82% (600 mg, 1.56 mmol).

Provenance & Evidence