反应详情

Piperazine-1-carboxylic acid tert-butyl ester (2.62 g, 14 mmol), cesium carbonate (5 g, 15 mmol) and ethyl bromoacetate (1.56 ml, 14 mmol) was stirred at room temperature for 1 h. The mixture was partitioned between water (200 ml) and diethyl ether (2×100 ml). The combined organic phases were dried over magnesium sulphate and concentrated to give a yellow oil which crystallised to give 4-ethoxycarbonylmethyl-piperazine-1-carboxylic acid tert-butyl ester as a pale yellow solid (2.6 g)

1. customThe mixture was partitioned between water (200 ml) and diethyl ether (2×100 ml)
2. dry with materialThe combined organic phases were dried over magnesium sulphate
3. concentrationconcentrated
4. customto give a yellow oil which
5. customcrystallised