Synthesis characterization and antibacterial activities of some new pyridazines and thieno[2,3-c]pyridazines

Abstract EN

Novel ethyl 6-phenyltetrazolo[1,5-b]pyridazine-8-carboxylate 4 was synthesized from the reaction of 2-chloro-4-carbethoxy-6-phenylpyridazine 2 with sodium azide in DMF.

Hydrazinolysis of compound 4 yielded the corresponding carbohydrazide, 5.

The reaction of 4-cyano-6-phenylpyridazine-3(2H)-thione 8 with bromoacetone and ethyl chloroacetate in the presence of sodium acetate afforded the novel thieno[2,3-c]pyridazine derivatives 9a,b.

The reaction of amino group in compounds 9a,b with 2,5-dimethoxytetrahydrofuran in acetic acid afforded the corresponding pyrrolyl derivatives 10a, b.

Similarly, treatment of compound 9b with succinc anhydride under reflux in acetic acid yielded the novel 3-(2,5-Dioxopyrrolidin-1-yl)- thienopyridazine 13.

Hydrazinolysis of compounds 10b and 13 produced the novel carbohydrazides, 11 and 19, respectively.

Structure of the new obtained compounds were established by elemental analyses and spectral data.

The new compounds were also screened for their antibacterial activity.