反应详情

To a solution of 2.6 g triphosgene and 1.7 ml cyclobutanol in 40 ml dichloromethane were added 6.2 ml triethylamine dropwise at 0° C. After 30 minutes 4.4 ml benzyl 1-piperazinecarboxylate and 3.2 ml triethylamine were added at 0° C. The reaction mixture was allowed to warm to RT for 16 h. Excess triphosgene was destroyed by adding a solution of 2 g NaOH in 200 ml water and stirring for 2 h. The layers were separated, the organic layer dried over MgSO4 and concentrated. The crude product thus obtained was purified by chromatography on silica using heptane/ethyl acetate 4/1 to 2/1 as eluent. Yield: 5.9 g.

1. customExcess triphosgene was destroyed
2. additionby adding a solution of 2 g NaOH in 200 ml water
3. customThe layers were separated
4. dry with materialthe organic layer dried over MgSO4
5. concentrationconcentrated