Hydrazine and phenylhydrazine undergo 1 : 2 addition to the carbonitrile function of 4-oxo-4H-[1]benzopyran-3-carbonitriles (1; X = H, Me, Cl, and Br) to form the iminohydrazine intermediates (2; non-isolable when R = H, and isolable when R = Ph) that further cyclise to yield 3-amino-[1]benzopyrano[4,3-c]pyrazoles (5) and 3-amino-4-(2-hydroxybenzoyl)-1-phenylpyrazoles (7; R = Ph) respectively. Hydroxylamine by similar 1 : 2 addition to the carbonitriles (1) gives 3-[hydroxyamino(imino)methyl]-4-oxo-4H-[1]benzopyrans (9), which undergo no further transformation under acidic conditions. In their reactions with the carbonitriles (1) or 4-oxo-4H-[1]benzopyran-3-carbaldehyde oximes (15), reactive methylene compounds such as acetylacetone, ethyl acetoacetate, diethyl malonate, and ethyl cyanoacetate in the presence of a base undergo Michael addition to the γ-pyrone system with concomitant opening of the pyrone ring and subsequent cyclisation to give benzopyrano[2,3-b]pyridine derivatives, (11), (12), (13), and (14), respectively.

中文翻译：

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杂环系统。第6部分。4-oxo-4 H- [1]苯并吡喃-3-甲腈与肼，苯肼，羟胺和某些反应性亚甲基化合物的反应

肼和苯肼在4-oxo-4 H- [1]苯并吡喃-3-腈（1; X = H，Me，Cl和Br）的腈官能团中进行1：2加成反应生成亚氨基肼中间体（2;当R = H时不可分离，当R = Ph时可分离，进一步环化生成3-氨基-[1]苯并吡喃并[4,3- c ]吡唑（5）和3-氨基-4-（2-羟基苯甲酰基） ）-1-苯基吡唑（7； R = Ph）。通过类似地将1：2的羟胺加至腈（1），得到3- [羟基氨基（亚氨基）甲基] -4-氧代-4 H- [1]苯并吡喃（9），其在酸性条件下不进行进一步的转化。在与腈（1）或4-oxo-4 H的反应中-[1]苯并吡喃-3-甲醛肟（15），反应性亚甲基化合物，如乙酰丙酮，乙酰乙酸乙酯，丙二酸二乙酯和氰基乙酸乙酯，在存在碱的情况下会经历迈克尔加成反应，并同时打开γ-吡喃酮体系吡喃环和随后的环化分别得到苯并吡喃并[2,3- b ]吡啶衍生物，分别为（11），（12），（13）和（14）。