反应详情

1-(Benzyloxycarbonyl)-4-(tert-butoxycarbonyl)piperazine-2-carboxylic acid (1-JJ, 1.07 g, 2.9 mmol, Small Molecules, Inc., Hoboken, N.J. USA) was dissolved in 10 mL of dry methanol and trimethylsilyl diazomethane (2.0 M in diethyl ether, Aldrich) was added dropwise with stirring at rt until a slight yellow color persisted. The solution was then concentrated under reduced pressure, and flash chromatography (0-50% EtOAc/hexanes elution) gave 1-benzyl 4-tert-butyl 2-methyl piperazine-1,2,4-tricarboxylate (compound II-JJ) as a colorless oil: [M+Na]+=401.2 (35%); [M-Boc+H]+=279.1 (100%).

1. concentrationThe solution was then concentrated under reduced pressure, and flash chromatography (0-50% EtOAc/hexanes elution)