Abstract
The reaction of 5,6,7,8-tetrahydro-4H-cyclohepta[b]thiophene derivatives 3a,b with acetic anhydride in presence of glacial acetic acid produced the acetamido derivatives 4a,b. Cyclization of the latter compounds gave the annulated products 5a,b. Compounds 3a,b reacted with one of the activated methylene groups of malononitrile (2a) and afforded compounds 7a,b through internal cyclization of the intermediates of compounds 6a,b. The latter products were reacted with the cyclic ketones 8a,b,c in presence of elemental sulphur and afforded compounds 9a-f. Compounds 3a,b reacted with different types of aldehydes 10a,b,c to produce compounds 11a-f. Finally the productslla-f reacted with hydrazine hydrate (12) affording compounds 14a-f via the proposed intermediate formation of compounds 13a-f. The antitumor activities of the synthesized compounds were tested using three different cell lines.