PYRIDAZINE DERIVATIVES AND RELATED-COMPOUNDS .3. SOME REACTIONS WITH 4-CYANO-3(2H)-PYRIDAZINETHIONE

The reaction of 5-amino-3,4-diphenylthieno{[}2,3-c]pyridazine-6-carboxamide 2 with form-amide, acetic anhydride and carbon disulphide yielded pyrimido{[}4',5':4,5]thieno{[}2,3-c]-pyridazin-4-one derivatives. Pyrimido{[}4,5-c]pyridazinethione and dithione derivatives were obtained by cyclocondensation of 3-amino-5,6-diphenylpyridazine-4-carbonitrile (8) with phenyl isothiocyanate and carbon disulphide, respectively. Tetrahydropyridazino{[}3,4-b]-quinoline (1 1) was prepared by reaction of 8 with cyclohexanone in presence of zinc chloride.