反应详情

Methyl 3-chloro-1-methyl-4,5-dihydro-1H-pyrazole-5-carboxylate (21 g, 119 mmol) was added drop wise to sodium hypochlorite (95 ml, 155 mmol) under ice cooling. Then, the ice bath was removed and stirring continued for 72 h. The organic phase was separated, washed with Na2S2O3 (10% aqueous solution) and water, dried over Na2SO4 and the solvent removed under reduced pressure. The resulting oil was purified by distillation (bp 35° C., 0.2 mbar) followed by column chromatography (eluent 80% hexane in EtOAc) to yield 6.0 g (29%) of the title compound. [1H-NMR (DMSO-d6, 360 MHz) δ 6.96 (s, 1H), 6.80 (s, 1H), 4.07 (s, 3H), 3.86 (s, 3H)]

1. customThen, the ice bath was removed
2. customThe organic phase was separated
3. washwashed with Na2S2O3 (10% aqueous solution) and water
4. dry with materialdried over Na2SO4
5. customthe solvent removed under reduced pressure
6. distillationThe resulting oil was purified by distillation (bp 35° C., 0.2 mbar)