Synthesis of 2-[4-(2-chlorobenzyl)-3-methyl-6-oxopyridazin-1(6H)-yl]acetohydrazide

Pyridazines are of chemical and biological interest. They have been reported to be anticonvulsive agents [1], [2]. Furthermore, BELLASIO et al. have described the antihypertensive effects of hydrazinopyridazine compounds [3]. In continuation of this line of investigation, we have synthesized compound (I); it will be subjected to further pharmacological investigations, especially tests of its anticancer activity.

To ( 0.96 g, 3 mmol) of ethyl [4-(2-chlorobenzyl)-3-methyl-6-oxopyridazin-1(6H)-yl)] acetate (I), was added 10 ml of hydrazine hydrate. The mixture was placed in a pyrex tube which was then introduced into a Maxidigest MX 350 Prolabo microwave[4] monomode reactor and refluxed for 10 min on 60 w as irradiation power. After cooling, the product precipitates, and then is recristallised in absolute ethanol, yield : 80 % of (II) solid.

Melting point: 201-205°C

IR (KBr, cm^-1): 3352(NH), 1682 , 1469 , 1622 (C = O)

¹HNMR (300.14 MHz, CDCl₃) δ (ppm): 2.49 (s, 3H, CH₃), 3.97 (s, 2H, CH₂), 4.21 (s, 2H, NH₂), 4.52 (s, 2H, CH₂), 6.03 (s, 1H, H4), 7.53 (m, 4H, H aromatic), 9.24 (s, 2H, NH₂).

¹³CNMR (75 MHz, CDCl₃) δ (ppm): 19.38 (CH₃), 35.6 (CH₂), 52.76 (CH₂), 126.98 (CH aromatic), 128.85 (CH aromatic), 130.25 (CH aromatic), 130.68 (CH aromatic), 132.6 (CH aromatic), 134.54, 135.43, 144.93, 146.03, 160.31 (C=O), 167.16 (C=O).