Expeditious and highly efficient protocol for the synthesis of novel diversely substituted thieno[2,3-b]thiophene

1,1′-(3-Methyl-4-phenylthieno[2,3-b]thiophene-2,5-diyl)bis(4,4,4 triethoxybut-2-en-1-one)-3 has been reported by one-pot reaction of enaminone derivative 2 with triethylorthoformate in fairly high yields. The hitherto unknown bis-hydroxyl amine derivatives 4via N-nucleophile under basic conditions is described. Additionally, the novel Compound 5 were synthesized by the cyclization of enaminone derivative 2 using AcOH with the aid of catalytic amount of AcONH4. Nevertheless, facile reaction sequences for the preparation of 6, 7, 8a-c, and 9a-c starting with 1,1′-(3-methyl-4-phenylthieno[2,3-b]thiophene-2,5-diyl)diethanone 1 have been developed. Finally, several bis-heterocycles 10a-f were synthesized through a stepwise formation of hydrazone followed by a Michael 1,4-addition of the nucleophile nitrogen atom and provides a convenient access to an important class of nitrogen heterocycles.