Acetic Acid → (2R,3R)-N-tert-Butyloxycarbonyl-3-(tert-butyldimethylsiloxy)-2-[(3-chloro-4-cyano-2-methylphenylamino)methyl]pyrrolidine

Participants

Reaction Steps

To a solution of (2S,3R)-3-(tert-Butyldimethylsilanyloxy)-2-formyl-pyrrolidine-1-carboxylic acid tert-butyl ester (51C) (661 mg, 2.0 mmol) in 5% DMF in CH2Cl2 (10 mL) at rt was added 4-amino-2-chloro-3-methyl-benzonitrile (340 mg, 2.04 mmol) followed by NaBH(OAc)3 (636 mg, 3.0 mmol) and HOAc (180 μL, 3 mmol). The reaction was stirred under nitrogen at rt for 18 h. Additional portions of NaBH(OAc)3 (424 mg, 2.0 mmol) and HOAc (120 μL, 2 mmol) were added, and the reaction was stirred for an additional 18 h. The reaction was diluted with EtOAc (50 mL) and the organic layer was washed with saturated aqueous NaHCO3 (50 ml), dried (MgSO4), filtered and concentrated. Purification via flash chromatography (silica gel, 0 to 15% EtOAc/hexanes) provided the title compound (605 mg, 1.26 mmol, 63%). MS m/z 480 [M+H]+.

Provenance & Evidence