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

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. [ABSTRACT FROM AUTHOR]