Syntheses, Characterization and Crystal Structures of N′-(5-Chloro-2-Hydroxybenzylidene)-4-Dimethylaminobenzohydrazide and N′-(2,4-Dichlorobenzylidene)-4-Dimethylaminobenzohydrazide

Abstract

The hydrazone compounds, N′-(5-chloro-2-hydroxybenzylidene)-4-dimethylaminobenzohydrazide (1) and N′-(2,4-dichlorobenzylidene)-4-dimethylaminobenzohydrazide (2), have been synthesized by the condensation reaction of equimolar quantities of 4-dimethylaminobenzohydrazide with 5-chlorosalicylaldehyde and 2,4-dichlorobenzaldehyde, respectively, in methanol. The compounds were characterized by elemental analysis, IR, ¹HNMR spectra, and single crystal X-ray diffraction. Compound 1 crystallizes in the monoclinic space group C2/c with unit cell dimensions a = 35.014(3) Å, b = 10.407(2) Å, c = 18.505(2) Å, β = 112.046(2)°, V = 6250.0(15) Ǻ³, Z = 16, R ₁ = 0.0624, and wR ₂ = 0.1187. Compound 2 crystallizes in the triclinic space group P-1 with unit cell dimensions a = 12.625(2) Å, b = 12.688(3) Å, c = 13.005(2) Å, α = 101.271(2)°, β = 112.945(1)°, γ = 104.966(2)°, V = 1747.6(6) Ǻ³, Z = 2, R ₁ = 0.0523, and wR ₂ = 0.1138. In the asymmetric unit of each compound, there exists two hydrazone molecules linking together by an N–H⋯O hydrogen bond. Furthermore, compound (2) contains one methanol molecule and one water molecule of crystallization.

Graphical Abstract

Two new hydrazone compounds, N′-(5-chloro-2-hydroxybenzylidene)-4-dimethylaminobenzohydrazide and N′-(2,4-dichlorobenzylidene)-4-dimethylaminobenzohydrazide, have been synthesized and structurally characterized.