Steric effects in the reactions of αβ-unsaturated ketonep-tolylsulphonylhydrazones: a route to 1,2-benzodiazepines via 1,7-ring closure of 1,1-diaryl-3-diazoalkenes
作者:John T. Sharp、Robert H. Findlay、Peter B. Thorogood
DOI:10.1039/p19750000102
日期:——
substituents on the reactions of the sodium salts of αβ-unsaturated ketone tosylhydrazones has been studied. The tosylhydrazone salts of acyclic αβ-unsaturated ketones and those of 2-methylenecyclohexanones underwent ready thermal 1,5-ring closure to give pyrazoles but the reactions of some 2-methylenecyclopentanone tosylhydrazones were atypical. Although 2-methylenecyclopentanone tosylhydrazone salts having a
研究了空间效应和取代基对αβ-不饱和酮甲苯磺酰hydr的钠盐反应的影响。无环αβ-不饱和酮的甲苯磺酰salts盐和2-亚甲基环己酮的甲苯磺酰salts盐已进行热1,5-环热封,得到吡唑,但某些2-亚甲基环戊酮甲苯磺酰hydr的反应是不典型的。尽管具有β-氢原子的2-亚甲基环戊酮甲苯磺酰salts盐以高产率环化得到1 H-吡唑,但是ββ-二烷基和ββ-二芳基类似物均不能给出3 H-吡唑。前者经羧基途径分解得到二烯,而后者经1,7环封闭得到3 H-1,2-苯并二氮杂s。研究了溶剂质子性对其中一些反应的影响,并讨论了吡唑和苯并二氮杂pine形成的机理。3 H-吡唑,3 H -1,2-苯并二氮杂和1 H -2,3-苯并二氮杂的13 C nmr光谱显示,环的大小强烈影响与偶氮基相连的饱和碳原子的化学位移。