反应详情

A mixture of 5-nitroindoline-2,3-dione (305 mg, 1.587 mmol), 2,2-dimethylpropane-1,3-diol (165 mg, 1.587 mmol) and p-toluenesulfonic acid monohydrate (catalytic amount) in cyclohexane (9 ml) was stirred at reflux temperature (removing water by a Dean-Stark apparatus) for 6 hours. The reaction was cooled to room temperature and the solid was recovered by filtration and washed with petroleum ether, affording 5,5-dimethyl-5′-nitrospiro[[1,3]dioxane-2,3′-indolin]-2′-one (481 mg). that was used as such in the following step. MS/ESI+ 279.0 [MH]+.

1. temperatureat reflux temperature (
2. customremoving water by a Dean-Stark apparatus) for 6 hours
3. filtrationthe solid was recovered by filtration
4. washwashed with petroleum ether