反应详情

4,5-Dimethyl-2(3H)-oxazolethione [Bull. Soc. Chim. Belg. 70, 745, (1961)] (37.5 g, 0.29 m) in 2N aqueous sodium hydroxide (150 ml) was stirred at room temperature during the dropwise addition of dimethyl sulphate (40.0 g, 0.317 m). The mixture was stirred for 4 hours at room temperature and then warmed to 50° C, cooled, and the aqueous phase extracted with diethyl ether. Evaporation of the solvent and distillation of the residue under reduced pressure gave 33.85 g (81%) of the title product as a pale yellow oil, b.p. 82° C./13 mm.

1. temperaturewarmed to 50° C
2. temperaturecooled
3. extractionthe aqueous phase extracted with diethyl ether
4. customEvaporation of the solvent and distillation of the residue under reduced pressure