反应详情

The crude 4-ethoxycarbonylethyl-1-formylpiperazine (114 g) prepared as described above is dissolved in water (500 ml) and sodium tungstate dihydrate (7.25 g) is added to the solution. At a temperature of 30°-35° C., 31% hydrogen peroxide (82 ml) is added dropwise to the solution and the mixture is stirred for one hour. The reaction mixture is stirred for 3 hours at room temperature and for another 5 hours at a temperature of 50°-55° C. The resulting reaction mixture is then shaken with ethyl acetate (300 ml). The aqueous layer is evaporated under reduced pressure to remove water to yield a dark brown oil. The oil is applied to a silica gel column chromatography for the purification (2 kg of silica gel, eluent; chloroform:methanol=10:1) and then is recrystallized from ethyl acetate to give 1-formyl-4-hydroxypiperazine (38.2 g), m.p. 118°-124° C.

1. stirringThe reaction mixture is stirred for 3 hours at room temperature and for another 5 hours at a temperature of 50°-55° C
2. customThe resulting reaction mixture
3. customThe aqueous layer is evaporated under reduced pressure
4. customto remove water
5. customto yield a dark brown oil
6. customThe oil is applied to a silica gel column chromatography for the purification (2 kg of silica gel, eluent; chloroform:methanol=10:1)
7. customis recrystallized from ethyl acetate