Reactions of some 4-dicyanomethylenepyran derivatives with malononitrile and hydrazines

4-Dicyanomethylene-2-phenyl-4H-benzob]pyran, the corresponding thiapyran, and 4-dicyanomethylene-2,6-diphenyl-4H-pyran react with malononilrile under basic conditions to give 5-amino-4-cyano-2-phenylbenzob]pyrano4,3,2-de] 1,6]naphthyridine, the corresponding thia-pyranonaphthyridine derivative, and 5-amino-6-cyano-2,8-diphenylpyrano4,3,2-de] 1,6]naphthyridine, respectively. Certain other related reactions were studied in the course of investigating the above reactions. Hydrazine hydrate and 4-dicyanomethylene-2-phenyl-4H-benzob]pyran gave 5-(2-hydroxyphenyl)-3-phenylpyrazole, and phenylhydrazine gave 5-(2-hydroxyphenyl)-1,3-diphenylpyrazole.