(1,1'-Biphenyl)-3-carboxylic acid, 3'-amino-, methyl ester → (R)-3'-[[2-[[2-(3-Chlorophenyl)-2-[[(tert-butyl)dimethylsilyl]oxy]ethyl][(tert-butoxy)carbonyl]amino]ethyl]amino]-[1,1'-biphenyl]-3-carboxylic acid methyl ester

Participants

Reaction Steps

To a stirred solution of 3′-amino-[1,1′-biphenyl]-3-carboxylic acid methyl ester (3.0 g) and (R)-[(tert-butoxycarbonyl)-[2-(tertbutyidimethylsilanyloxy)-2-(3-chlorophenyl)ethyl]amino}acetaldehyde (8.2 g) in anhydrous dichloromethane (65 mL) was added acetic acid (8 drops). After stirring for twenty-five minutes, sodium triacetoxyborohydride (5.6 g) was added and the reaction stirred overnight. The reaction was quenched with saturated aqueous sodium bicarbonate and more dichloromethane was added. The organic layer was dried over sodium sulfate and the solvent was removed under reduced pressure to yield a white foam. The residue was purified by silica gel chromatography and eluted with 9:1 hexane:ethyl acetate to provide the title compound as a white foam (5.62 g).

Provenance & Evidence