Effect of substituent in pyridine-2-carbaldehydes on their heterocyclization to 1,2,4-triazines and 1,2,4-triazine 4-oxides
作者:A. P. Krinochkin、D. S. Kopchuk、N. V. Chepchugov、I. S. Kovalev、G. V. Zyryanov、V. L. Rusinov、O. N. Chupakhin
DOI:10.1134/s1070428017070016
日期:2017.7
A series of substituted pyridine-2-carbaldehydes were brought into heterocyclization with isonitrosoacetophenone hydrazones, followed by aromatization by the action of oxidants or by dehydration in boiling acetic acid. As a result, substituted 3-(pyridin-2-yl)-1,2,4-triazines or 3-(pyridin-2-yl)-1,2,4-triazine 4-oxides were formed. 6-Formylpyridine-2-carbonitrile failed to undergo heterocyclization
将一系列取代的吡啶-2-甲醛与异亚硝基苯乙酮进行杂环化,然后通过氧化剂的作用或在沸腾的乙酸中脱水进行芳构化。结果,形成了取代的3-(吡啶-2-基)-1,2,4-三嗪或3-(吡啶-2-基)-1,2,4-三嗪4-氧化物。6-甲酰基吡啶-2-甲腈不能进行杂环化,6-甲基吡啶-2-甲醛和6-甲酰基吡啶-3-羧酸甲酯可以同时转化为1,2,4-三嗪和1,2,4-三嗪4-从6-溴吡啶-2-甲醛和6-甲酰基-3-苯基吡啶-2-腈中仅得到1,2,4-三嗪4氧化物。提出了一些合成初始吡啶甲醛的简便方法。