Synthesis of 4-Fluoromethylsydnones and their Participation in Alkyne Cycloaddition Reactions
作者:Robert S. Foster、Harry Adams、Harald Jakobi、Joseph P. A. Harrity
DOI:10.1021/jo400381a
日期:2013.4.19
We report the synthesis and some structural studies of 4-trifluoromethyl, 4-difluoromethyl-, and 4-monofluoromethylsydnones. All but the latter compounds are stable and represent effective precursors to a range of pyrazoles after cycloadditionreactions with alkynes. The cycloadditions are generally highly regioselective and provide 5-fluoromethylpyrazole products, although we have observed that Bn-substituted
A GC procedure for the simultaneous determination of hydrazine and benzylhydrazine in isocarboxazid raw material and tablet formulations has been developed. The method is based on the reaction of benzoyltrifluoroacetone with hydrazine and benzylhydrazine to form the corresponding pyrazole derivatives. The minimum detectable amounts of hydrazine and benzylhydrazine in isocarboxazid are 0.002 and 0.02%