O-(Benzotriazol-1-yl)-N,N,N',N'-tetramethyluronium tetrafluoroborate → Tert-butyl 2-((2-(4-chloro-3-fluorophenylamino)-2-oxoacetamido)(5-(hydroxymethyl)-4-methylthiazol-2-yl)methyl)piperidine-1-carboxylate

Participants

Reaction Steps

A mixture of 2-(4-chloro-3-fluorophenylamino)-2-oxoacetic acid (3′) (0.3 g, 1.378 mmol), TBTU (0.530 g 1.65 mmol) and TEA (0.166 g, 1.65 mmol) in DCM (20 ml) was stirred at RT for 1 h, then 2-[amino-(5-hydroxymethyl-4-methyl-thiazol-2-yl)-methyl]-piperidine-1-carboxylic acid tert-butyl ester (0.470 g, 1.378 mmol) was added and stirring was continued for 6 h. Reaction mixture was washed with 25% aqueous solution of K2CO3 (2×50 ml) and water (50 ml). The product was dried over Na2SO4 and evaporated. The residue was purified by column chromatography on silica gel (EtOAc/hexane1/1) to afford tert-butyl 2-((2-(4-chloro-3-fluorophenylamino)-2-oxoacetamido)(5-(hydroxymethyl)-4-methylthiazol-2-yl)methyl)piperidine-1-carboxylate (4′) (0.53 g, 72%) as a white solid; LC-MS (APCI+) m/z: calcd for C24H30ClFN4O5S: 540.16. found: 541 (M+H+).

Provenance & Evidence