Diisopropylethylamine → tert-Butyl-4-(1-{[4-(5-cyano-7-isopropyl-1,3-benzoxazol-2-yl)benzoyl]amino}-2-methoxy-2-oxoethyl)piperidine-1-carboxylate

Participants

Reaction Steps

At room temperature, a 2-dram vial equipped with a magnetic stirrer was charged with 4-(5-cyano-7-isopropyl-1,3-benzoxazol-2-yl)benzoic acid (INTERMEDIATE 2), 4-(amino-methoxycarbonyl-methyl)-piperidine-1-carboxylic acid tert-butyl ester, bromo-tris-pyrrolidino phosphonium hexafluorophosphate, and dimethylformamide (5 ml). To this mixture was added of N,N-diisopropylethylamine, dropwise. The reaction mixture was allowed to stir at room temperature for 3 d. The residue was purified by flash chromatography using a Biotage SP 1, 40M silica cartridge, eluting with a linear gradient of 20% to 100% hexanes in ethyl acetate over 15 column volumes to provide the title compound. Mass spectrum (ESI) 559.3 (M+1).

Provenance & Evidence