Reaction of 4chlorocoumarin3carbonitrile with ethyl thioglycolate and ethyl glycinate hydrochloride leads to a series of title products. Hydrazinolysis of amino thienocoumarin carboxylate afforded the hydrazi no derivative which underwent various reactions to build new heterocyclic rings containing thienocoumarin moiety. Chloro acetylation of aminoester compound afforded the chloro acetyl amino which underwent nu cleophilic substitution reactions various amines. The following treatment with formaldehyde under Mannich conditions afforded the corresponding imidazo derivatives. Reaction of chloroacetylamino with potassium thiocyanate yielded ethylpyrimidothieno coumarin sulfanylacetate which was used as a versatile precursor for synthesis of other heterocycles. On the other hand, reaction of chloro coumarin carbonitrile with hydrazine gave the aminopyrazolocoumaine which reacted with bifunctionally compounds to give the substituted py rimido derivatives. Diazotization and coupling of aminopyrazole with ethylcyanoacetate yielded ethylami notriazinopyrazolocoumarine carboxylate. Several of the compounds obtained demonstrated considerable antifungal and antibacterial activity in the in vitro test systems.