Diisopropylethylamine → (2S,5R)-4-[5-(4-Bromo-3-trifluoromethoxy-phenylcarbamoyl)-pyridin-2-yl]-2,5-dimethyl-piperazine-1-carboxylic acid tert-butyl ester

Participants

Reaction Conditions

Reaction Steps

To a solution of 4-bromo-3-trifluoromethoxy-phenylamine (190 mg, 0.74 mmol) and N,N-diisopropylethylamine (0.65 mL, 3.73 mmol; in N,N-dimethylacetamide (3 mL) was added a solution of (2S,5R)-4-(5-carboxy-pyridin-2-yl)-2,5-dimethyl-piperazine-1-carboxylic acid tert-butyl ester TFA (330 mg, 0.74 mmol; Preparation 26) and HCTU (401 mg, 0.97 mmol) in N,N-dimethylacetamide (3 mL). The reaction mixture was heated at 50° C. overnight. The reaction mixture was concentrated by rotary evaporation, extracted with ethyl acetate/sat. sodium carbonate, dried over sodium sulfate, filtered, concentrated and purified by silica gel chromatography (0-50% ethyl acetate:hexanes) to provide the title compound (155 mg, yield 36%). (m/z): [M+H]+ calcd for C24H28BrF3N4O4 573.12, 575.12 found 575.5.

Provenance & Evidence