Synthesis of New Polyfused Thienopyrimidine, Thienopyridine, Thienothiazine, Thienoxazine, and Thienodiazepine Derivatives

Abstract

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 CS 2 , NaOH and CH 3 I 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 CS 2 , phenyl (benzoyl)isothiocyanate and phenylisocyanate to get the described products 14-19 , respectively. On reacting compound 1 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 .

Keywords:

• Thieno(2,3-b)thiophene
• Thienoimidazolino(1,4)diazepine
• Thienoimidazolinopyrimidine
• Thienopyridine
• Ptc