反应详情

To a refluxing mixture of 21.5 g 4-methyl-2-(4-trifluoromethyl-phenyl)-oxazole-5-carboxylic acid ethyl ester (synthesized according to the method described for 5-chloromethyl-4-methyl-2-[2-(4-trifluoromethyl-phenyl)-ethyl]-oxazole from 4-trifluoromethyl-benzamide and 2-chloroacetoacetate) in 180 ml tetrachloro-methane were added portionwise a mixture of 15.4 g N-bromosuccinimide and 4.73 g 2,2′-azobis(2-methylpropionitrile). The reaction mixture was heated under reflux for five hours. The cooled reaction mixture was filtered over a celite pad, the filtrate was evaporated in vacuo and the resulting residue was purified by chromatography on silica gel with the eluent petroleum benzene:dichloromethane=7:3 to provide 18.5 g 4-bromomethyl-2-(4-trifluoromethyl-phenyl)-oxazole-5-carboxylic acid ethyl ester.

1. customsynthesized
2. additionwere added portionwise
3. temperatureThe reaction mixture was heated
4. temperatureunder reflux for five hours
5. customThe cooled reaction mixture
6. filtrationwas filtered over a celite pad
7. customthe filtrate was evaporated in vacuo
8. customthe resulting residue was purified by chromatography on silica gel with the eluent petroleum benzene