Heterocyclic Tautomerism. IX. Structural Revision of a Series of Pharmacologically Active Pyridazines

Article abstract of DOI:10.1071/CH9951601

On the basis of 1H n.m.r. n.O.e. measurements and X-ray crystal structure determination, it is shown that a large series of pharmacologically active pyridazine derivatives should be represented as aromatic pyridazine tautomers , rather than the previously reported arylidene-4,5-dihydropyridazines .Crystals of (7b) are monoclinic P2₁/c, a 13.312(3), b 7.269(1), c 11.753(2) Angstroem, β 101.38(3) deg, Z = 4; the structure was refined to a conventional R 2?(I)> 0.037.