Syntheses and crystal structures of benzyl N′-[(E)-2-hydroxybenzylidene]hydrazinecarboxylate and benzyl N′-[(E)-5-bromo-2-hydroxybenzylidene]hydrazinecarboxylate

Abstract

Benzyl N′-[(E)-2-hydroxybenzylidene]hydrazinecarboxylate, C15H14N2O3 (I) and benzyl N′-[(E)-5-bromo-2-hydroxybenzylidene]hydrazinecarboxylate (II), C15H13BrN2O3, have been synthesized by the reaction of either 2-hydroxybenzaldehyde or 5-bromo-2-hydroxybenzaldehyde with benzyl carbazate, respectively. Both the compounds crystallize in the monoclinic crystal system with space groups Pn (Z′ = 1, I) and P21/c (Z′ = 2, II). Molecular conformations in each structure are similar, and both structures feature strong intramolecular O—H...N hydrogen bonds, which form S(6) ring motifs. There are also strong N—H...O and weak C—H...O hydrogen bonds in both structures, but their modes of packing within their respective crystals are markedly different. Some comparisons are made with the structures of a few related compounds.