THE COUPLING reaction of 2-diazo-3-cyano-4,5,6,7-tetrahydrobenzo [b] thiophene (2) with the 2-aminoprop-1-ene-1,1,3-tricarbonitrile (3) gave the hydrazone derivative (4). Compound 4 underwent ready cyclization to give the pyridazine derivative (5). The reaction of 4 with hydrazines gave pyrazole derivatives (6a,b). On the other hand, the reaction of 4 with active methylene reagents gave the pyridazine derivatives (7a,b). The latter products were cyclized into the pyrido [3,2-c] pyrimidine derivatives 8a and 8b, respectively. The reaction of 4 with phenylisothiocyanate gave the 1,2,4-triazine derivative (9). The antidepressant and sedative activities of the newly synthesized products were measured.