Synthesis, structure characterization and biological evaluation of new 6,8-dichloro-2-methyl-4H-chromen-4-one derivatives

The typical active methyl functionality of 6,8-dichloro-2-methyl-4H-chromen-4-one is utilized to obtain 2-styrylchromones, pyruvate ester and phthalide via reactions with aromatic carboxaldehydes, diethyl oxalate and phthalic anhydride respectively. The phthalide provides illustrative example to convert a heterocyclic compound to an aliphatic one via the effect of alcoholic sodium methoxide. Bromination and cycloaddition reactions of 2-styrylchromones afford vicinal dibromide and adducts respectively. This work presents to the art a typical example of heterocyclic systems transformations through the conversion of the starting chromone to coumarin under the influence of thionyl chloride followed by aqueous potassium hydroxide. Some heterocyclic systems like pyrazole, isoxazol and quinolinone are obtained from the target chromone by treatment with hydrazines, hydroxylamine hydrochloride and ammonium acetate respectively. Thiation of starting chromone interestingly affords a dithiated product instead of the expected monothiated one. Antibacterial and antifungal activities of some synthesized compounds have been screened

Synthesis and reactions of (Z)-2-imino-5-(3,4,5-trimethoxy benzylidene)thiazolidin-4(H)one

5-Arylmethylene-2-imino-4-oxo-2-thiazolidine 3 was obtained as the sole product from the reaction of α-cyano-3,4,5-trimethoxy cinnamonitrile and/or ethyl-α-cyano-3,4,5-trimethoxy cinnamate (1a,b) with 2-imino-4-oxo-2-thiazolidine 2. The reaction of 3 with benzyl amine gave the imidazolidin-4(H)one derivative 4 while with hydrazine hydrate afforded the dimeric product 5. Also, reaction of thiazolidinone derivative 3 with piperidine gave thiazol-4(5H)one derivative 6 which on treatment with Grignard reagent and active methylene compounds afforded thiazolidin-4-one derivatives 7-9, respectively. Compound 6 was converted to the potassium salt 10 which treated with acetic acid, ethyl chloroacetate and furoyl chloride to give the compounds 11-13, respectively. The structures of all new compounds were evidenced by microanalytical data and spectral data

Facile synthesis of new fused and non-fused heterocyclic systems from a γ-ketoacid

The chemical reactivity of 4-(2-tetryl)-4-oxobut-2-enoic acid towards carbon, nitrogen, oxygen, sulfur nucleophiles and binucleophiles namely o-phenylenediamine, o-aminophenol, and o-aminothiophenol has been studied. The investigated nucleophilic reactions result in the formation of heterocyclic compounds with fused and non-fused systems namely, pyridazinone, tetrhydroquinoline, quinoxalone, oxazinone, thiazole and benzocoumarin