反应详情

A solution of 1.6 g of methylamine in 35 ml of xylene prepared at 0° C. is flown to the solution of 13.0 g of 8-benzyl-4-methylene-2-oxo-1,3-dioxa-8-azaspiro[4,5]decane in 30 ml of xylene under stirring. The reaction is exothermic, thus the temperature of the reaction mixture increases up to 55° to 60° C. Thereafter, the heterogeneous reaction mixture is heated to a temperature of 100° to 102° C., maintained at the same temperature for 10 minutes, then 0.2 g of p-toluenesulfonic acid monohydrate is added to the solution and the reaction mixture is boiled while the water formed in the reaction is azeotropically distilled out. After termination of the reaction the mixture is cooled down to room temperature, washed with 5% by weight aqueous sodium hydroxide solution and after separation the xylene phase is washed to neutral with water. The organic phase is dried over anhydrous sodium sulfate and evaporated under reduced pressure. The residue is recrystallized from a mixture of ethanol and diisopropyl ether under clarifying by activated carbon to obtain the title compound in 96.7% yield, m.p.: 96°-97° C.

1. temperaturethus the temperature of the reaction mixture increases up to 55° to 60° C
2. temperatureThereafter, the heterogeneous reaction mixture is heated to a temperature of 100° to 102° C.
3. temperaturemaintained at the same temperature for 10 minutes
4. customformed in the reaction
5. distillationis azeotropically distilled out
6. customAfter termination of the reaction the mixture
7. washwashed with 5% by weight aqueous sodium hydroxide solution
8. customafter separation the xylene phase
9. washis washed to neutral with water
10. dry with materialThe organic phase is dried over anhydrous sodium sulfate
11. customevaporated under reduced pressure
12. customThe residue is recrystallized from a mixture of ethanol and diisopropyl ether under clarifying by activated carbon