Synthesis, reactions, and biological activities of some new thieno[3,2-c]quinoline and pyrrolo[3,2-c]quinoline derivatives.

2-Bromo-4-fluoroaniline (1) was condensed with ethyl 2-cyano-3-ethoxyacrylate (2) in ethanol to afford 3, which upon refluxing in paraffin oil at 250°C gave 8-bromo-3-cyano-6-fluoroquinoline-4(1H)-one (4). Then, compound 4 was taken as a versatile building block that allows the synthesis of thieno[3,2-c]quinoline, pyrrolo[3,2-c]quinoline, and N-methylpyrrolo[3,2-c]quinoline systems. The newly synthesized compounds and their derivatives were characterized by elemental analysis and spectroscopy (IR, (1)H NMR, (13)C NMR, and mass). Furthermore, some of these synthesized compounds were screened for their biological activities against various pathogenic bacterial and fungal strains. Our results demonstrate that most of the synthesized compounds possess a significant broad antibacterial activity against all strains of both gram-positive and gram-negative bacteria. In addition, compound 5 showed remarkable antifungal activity.

Synthesis and antimicrobial activity of new heterocyclic compounds containing thieno[3,2-c] coumarin and pyrazolo[4,3-c] coumarin frameworks.

Reaction of 4-chlorocoumarin-3-carbonitrile with ethyl thioglycolate and ethyl glycinate hydrochloride leads to a series of title products. Hydrazinolysis of amino thienocoumarin carboxylate afforded the hydrazine 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 nucleophilic substitution reactions various amines. The following treatment with formaldehyde under Mannich conditions afforded the corresponding imidazo derivatives. Reaction of Ghloroacetylamino 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 carbo nitrile with hydrazine gave the aminopyrazolocoumaine which reacted with bifunctionally compounds to give the substituted pyrimido derivatives. Diazotization and coupling of aminopyrazole with ethylcyanoacetate yielded ethylaminotriazinopyrazolocoumarine carboxylate. Several of the compounds obtained demonstrated considerable antifungal and antibacterial activity in the in vitro test systems.

Synthesis and reactions of some new pyrrolylthieno[2,3-D]quinoxaline and pyrrolopyrazinothienoquinoxalines.

The synthesis of 3-pyrrolyl-2-substituted thieno[2,3-b]quinoxalines from the precursor 3-amino derivatives are described. Synthesized compounds were subjected to reactions with other reagents to synthesize poly-fused heterocyclic incorporated thienoquinoxaline moiety. Some of the synthesized compounds were screened for their antibacterial and antifungal activities.