While 2-acetyl and 2-benzoyl-3-aminobenzofurans did not react with hydrazine, monomethyl- and N,N-dimethylhydrazine to give the related hydrazones, their 3-N-(p-toluenesulfonyl) derivatives afforded them smoothly in good yields. Depending upon reaction conditions, products arising from hydrazone cyclization to benzofuropyrazoles and/or from furan ring cleavage at the C2O bond to give 5-(2-hydroxyphenyl)pyrazoles
尽管2-乙酰基和2-苯甲酰基-3-
氨基
苯并呋喃不与
肼,单甲基和N,N-二甲基
肼反应生成相关的,但它们的3- N-(对
甲苯磺酰基)衍
生物以良好的收率平稳地提供了它们。取决于反应条件,还形成了由环化为
苯并呋喃并
吡唑和/或在C 2 O键处
呋喃环裂解而产生5-(2-羟基苯基)
吡唑的产物。这些产物的形成取决于的构型并进行了讨论。仅(E)-异构体似乎发生
呋喃开环。在室温下的酸性介质中,或单甲基hydr会生成相同的相关α-嗪。微量分析,红外,紫外1 H-nmr和ms光谱与所提出的结构一致。