Synthesis and Crystal Structures of N′-(5-Bromo-2-hydroxy-3-methoxybenzylidene)-4-methoxybenzohydrazide and 4-{[1-(5-bromo-2-hydroxy3-methoxyphenyl)methylidene]amino}-1-methyl-2-phenyl-1,2-dihydropyrazol-3-one

Abstract

Two Schiff bases, N′-(5-bromo-2-hydroxy-3-methoxybenzylidene)-4-methoxybenzohydrazide (1) and 4-{[1-(5-bromo-2-hydroxy3-methoxyphenyl)methylidene]amino}-1-methyl-2-phenyl-1,2-dihydropyrazol-3-one (2), have been synthesized by the reaction of 5-bromo-3-methoxysalicylaldehyde with 4-methoxybenzohydrazide and 4-aminoantipyrine, respectively. The compounds were characterized by elemental analysis and X-ray single crystal determination. Compound (1) crystallizes in the monoclinic space group P21/c with unit cell dimensions a = 14.919(1), b = 8.249(2), c = 41.515(4) A, β = 111.054(2)°, V = 4768.1(13) A3, Z = 12, R 1 = 0.0765, and wR 2 = 0.1733. Compound (2) crystallizes in the monoclinic space group P21/c with unit cell dimensions a = 7.826(1), b = 13.791(1), c = 17.090(2) A, β = 100.137(2)°, V = 1815.7(3) A3, Z = 4, R 1 = 0.0334, and wR 2 = 0.0736. Both molecules of the compounds display E configuration with respect to the C=N double bonds. In the crystal structure of (1), molecules are linked via intermolecular N–H···O hydrogen bonds, forming chain structure along the a axis. In the crystal structure of (2), molecules are linked via weak Br···O interactions, forming chain structure along the c axis. The synthesis and crystal structures of two new Schiff bases have been prepared and characterized.