N'-Benzylidene-4-pyridinecarboxylic acid hydrazide synthesis

Yield:533-02-8 95%

Reaction Conditions:

with acetic acid in ethanol; for 0.25 h;Sonication;

Steps:

General procedure for synthesis of isonicotinoylhydrazones 3a-e

General procedure: Isoniazid (1) (0.144 g, 1.05 mmol) and the appropriate aldehyde 2a-e (1.0 mmol) were mixed in ethanol (20 mL)in the presence of 10 mol% of acetic acid as catalystin a 50 mL beaker. The reaction mixture was sonicatedfor 15 min using an ultrasonic probe. After cooling toroom temperature, the solvent was evaporated underreduced pressure. The obtained solids were washed withwater (4 × 10 mL) under vigorous stirring followed bycentrifugation. Afterward, the products were dried underreduced pressure and isolated in satisfactory purity withoutneed of subsequent purification steps. (E)-N’-Benzylideneisonicotinohydrazide (3a) Yield: 95%; mp 190-191 °C (194-196 °C);24 IR (UATR) / cm-1 3,198 (NH), 3,027 (CH), 1,682 (C=O), 1,562(C=N), 1,282, 1,149, 766, 684; 1H NMR (60.1 MHz,DMSO-d6) d 7.48-7.91 (m, 7H, Ar-H, Py-H*), 8.52 (s, 1H,vinylic-H), 8.81 (d, 2H, J 5.9 Hz, Py-H), 12.08 (s, 1H, NH);13C NMR (100.6 MHz, DMSO-d6) d 121.5, 128.8, 130.3,134.0, 140.5, 149.1, 150.3, 161.6; HRMS (FTMS + pESI)m/z, calcd. for C13H11N3O [M + H]+: 226.0975, found:226.0957; *Py-H: pyridine hydrogens.

References:

Gazzi, Thais P.;Rotta, Mariane;Villela, Anne D.;Rodrigues, Valn's;Martinelli, Leonardo K.B.;Sales, Francisco Adilson M.;Silva De Sousa, Eduardo Henrique;Campos, Maria Martha;Basso, Luiz Augusto;Santos, Diógenes S.;Machado, Pablo [Journal of the Brazilian Chemical Society,2017,vol. 28,# 10,p. 2028 - 2037]