Synthesis of new polyfused thienopyrimidine, thienopyridine, thienothiazine, thienoxazine, and thienodiazepine derivatives

3,4-Diamino-2-carbethoxy-5-cyanothieno(2,3-b)thiophene (1) was treated with ethylenediamine to afford 3,4-diamino-2,5-bi[2-(4,5-dihydro-1H-imidazole-2-yl]-thieno(2,3-b)thiophene 2, which in turn was treated with chloroacety chloride to give bis[imidazolothieno diazepine] derivative 3 and with each of p-chlorobenzaldehyde, triethyl orthoformate, and Lawesson's reagent (LR) to yield bis[imidazolothienopyrimidine] derivatives 4-6. Compound 1 was subjected to Mannich reaction to afford Mannich bases 7 and 8a,b. The later products (8a,b) were treated with malononitrile yielding 9a and 9b. treatment of compound 1 with CS2, NaOH and CH3I produced compounds 10 and 11. The reaction of compound 10 with each of o-aminothiphenal, o-phenylenediamen, hydrazine hydrate, and phenylhydrazine afforded compounds 12a,b, 13a,b. Compound 1 was allowed to react with CS2, phenyl (benzoyl)isothiocyanate and phenylisocyanate to get the described products 14-19, respectively. On reacting compound I with ethylcyanoacetate thieno(2,3-b)pyridine derivative 21 was obtained through the intermediate 20. Finally, compound 1 was treated with malononitrile to yield compound 22.