Synthesis and anti-bacterial activity of some new thienopyridazines, pyridazothienooxazinone, and pyrimidothienopyridazines

Abstract EN

Refluxing of 3-chloro-4-cyano-6-phenylpyridazine 3, with thiourea furnished 4-cyano-6- Phenylpyridazine-3(2H)-thione 4.

The novel thieno [2, 3-c]pyridazines 5a-c and 6a-c were achieved by cyclization of compound 4 with active halomethylene in the presence of sodium ethoxide and / or with N-arylchloroacetamide in the presence of potassium carbonate, respectively.

Saponification of compound 5a with ethanolic sodium hydroxide, and subsequent cyclization, with acetic anhydride under reflux, afforded novel pyridazino [3′, 4′ : 4, 5] thieno [3, 2-d]oxazin-4-one derivative 8.

The latter compound was reacted with aniline, hydrazine hydrate, urea / thiourea / ammonium acetate, and thiosemicarbazide to produce pyrimido [4′, 5′: 4, 5] thieno [2, 3-c] pyridazine derivatives 10 -14, respectively.

Condensation of 7-minopyrimidothienopyridazine 11 with acetic anhydride, furfural and triethyl orthoformate, gave new 7-functionalized pyrimidothienopyridazines 15-17, respectively.

The structures of the synthesized compounds were confirmed by their analytical and spectral data.

The prepared compounds were also screened for their antibacterial activity.