Novel azaenamines incorporating a tetrahydrothiophene moiety were prepared. Michael addition of an azaenamine with alpha,beta-unsaturated nitriles took place to give [1]benzothieno[3',2':5,6]pyrimido[1,2-b]pyridazine (thia- triaza-benzo[a]fluorene) derivatives. The condensation with malononitrile resulted in the formation of a [1]benzothieno[3',2':5,6]pyrimido[1,2-b]pyridazine-4-carbonitrile. The azaenamine also reacted with aldehydes and piperidine to give Mannich products.