Synthesis of 4, 4??dimethyl??3, 4??dihydro??3, 3, 5??trisubstituted??2H??pyrazoles and N??benzoyl derivatives: Method for “Hydrolysis” of unreactive amides and carbamates
…, A Choudhary, PC Vasquez
文献索引：Baumstark, Alfons L.; Choudhary, Anil; Vasquez, Pedro C.; Dotrong, My Journal of Heterocyclic Chemistry, 1990 , vol. 27, # 2 p. 291 - 294
Abstract Addition of organolithium reagents to 4, 4-dimethyl-3, 5-disubstituted-4H-pyrazoles produced a series of 4, 4-dimethyl-3, 4-dihydro-3, 3, 5-trisubstituted-2H-pyrazoles, 2–6, in good yield. The reaction was stereoselective: addition of organolithium compounds occurred only to carbon-3 of 4, 4-dimethyl-3-alkyl-5-aryl-4H-pyrazoles. The 3, 4-dihydro-2H-pyrazoles were found to be of high sensitivity to oxygen. For long term storage and ease of handling, ...
