Synthesis and reactions of 4-(p-methoxybenzyl)-6-[5,6,7,8-tetrahydro-2-naphthyl]-pyridazin-3(2H)-one

The condensation of 4-(p-methoxybenzyl)-6-[5,6,7,8-tetrahydro-2-naphthyl]-pyridazin-3(2H)-one (3), prepared by the reaction of 6-[5,6,7,8-tetrahydro-2-naphthyl]-4,5-dihydropyridazin-3(2H)-one (1) and anisaldehyde, with dimethyl sulphate, formaldehyde and acrylonitrile, and also the formation of the Mannich base, proceeded smoothly at the 2-position to give compounds 4,5,6,7, respectively. 4-p-Methoxybenzyl-3-chloro-6-[5,6,7,8-tetrahydro-2-naphthyl]-pyridazine (9) was prepared in law yield by the action of phosphorus oxychloride on 3. The reaction of 9 with benzylamine, aniline and piperidine gave 10a,b,c, respectively. 4-p-Methoxybenzyl-6-[5,6,7,8-tetrahydro-2-napthyl]pyridazine-3(2H)-thione (12) was prepared either by the action of thiourea on 9, or by the reaction of 3 with phosphorus pentasulphide. The reaction of these thiones with acrylonitrile, morpholine and piperidine to give 13 and 14 a,b, respectively, were also investigated.