Ethyl Acetate → 4-{5-[3-(5-tert-butyl-2-p-tolyl-2H-pyrazol-3-yl)-ureido]-pyridin-2-yl}-piperazine-1-carboxylic acid tert-butyl ester

Participants

Reaction Steps

Place 4-(5-amino-pyridin-2-yl)-piperazine-1-carboxylic acid tert-butyl ester (200 mg, 0.718 mmol), diisopropylethylamine (0.125 mL, 0.718 mmol), and (5-tert-butyl-2-p-tolyl-2H-pyrazol-3-yl)-carbamic acid, 2,2,2-trichloro-ethyl ester (Preparation 38, 291 mg, 0.718 mmol) in DMSO (5 mL) and heat to 75° C. for 17 hours. Cool to room temperature and add EtOAc and water. Separate organic layer and wash with saturated aq. sodium chloride (2×20 mL). Collect organic layer, dry over Mg2SO4, filter, and concentrate under reduced pressure. Subject residue to silica gel chromatography eluting with 0-70% EtOAc:hexane to yield 328 mg (85%) of 4-{5-[3-(5-tert-butyl-2-p-tolyl-2H-pyrazol-3-yl)-ureido]-pyridin-2-yl}-piperazine-1-carboxylic acid tert-butyl ester. MS(ES+): m/z=534.4 [M+H]).

Provenance & Evidence