CRYSTAL-STRUCTURES OF ANHYDRO-BASES OF 1 AND 2-(ETHOXYCARBONYLMETHYLO)-4-HYDROXYCINNOLINIUM HYDROXIDES

C12H12N2O3, M(r) = 232.24. (1): C2/c, Z = 8, a = 14.658(1), b = 4.9375 (4), c = 31.859(4) angstrom, beta = 98.710(6)-degrees. (2): P2(1)/c, Z = 4, a = 11.422(2), b = 4.8864(2), c = 21.176(3) angstrom, beta = 103 .29(3)-degrees. The study confirms significant contribution of quinoid diazine ring form in anhydrobase of 1-substituted 4-hydroxycinnoliniu m hydroxides. The phenomenon corresponds with a negative net charge at formerly positively charged N(1) atom, with fewer hydrogen contacts o f less negatively charged O(4) and with increased stacking in 1-substi tuted derivative, in comparison with 2-substituted structure.