A number of novel heterocyclic chalcone derivatives can be synthesized by thermal and microwave tools. Treatment of 4-(4-Acetylamino-and/or 4-bromo-phenyl)-4-oxobut-2-enoic acids with hydrogen peroxide in alkaline medium were afforded oxirane derivatives 2. Reaction of the epoxide 2 with 2-amino-5-aryl-1,3,4-thiadiazole derivatives yielded chalcone of imidazo[2,1-b]thiadiazole derivative 4 via two thermal routes.In one pot reaction of 4-bromoacetophenone, diethyloxalate, and 2-amino-5-aryl-1,3,4-thiadiazole derivatives in MW irradiation (W 250 and T 150˝C) under eco-friendly conditions afforded an unsuitable yield of the desired chalcone 4d. The chalcone derivatives 4 were used as a key starting material to synthesize some new spiroheterocyclic compounds via Michael and aza-Michael adducts. The chalcone 4f was similar to the aryl-oxo-vinylamide derivatives for the inhibition of tyrosine kinase and cancer cell growth. The electron-withdrawing substituents, such as halogens, and 2-amino-1,3,4-thiadiazole moeity decreasing the electron density, thereby decreasing the energy of HOMO, and the presence of imidazothiadiazole moiety should improve the antibacterial activity. Thus, the newly synthesized compounds were evaluated for their anti-bacterial activity against (ATCC 25923), (ATCC 10987), (ATCC 274,) and (SM514). The structure of the newly synthesized compounds was confirmed by elemental analysis and spectroscopic data.

An efficient method to obtain ethyl 5-amino-1-tosyl-1H-pyrazole-4-carboxylate (3) was outlined using condensation reactions of 4-methylbenzenesulfonylhydrazide with (E)-ethyl 2-cyano-3-ethoxyacrylate. The cyclocondensation reaction of this substrate and its hydrazide derivative with urea, thiourea, formamide, formic acid, D-glucose, o-phenylenediamine, 4-dimethylaminobenzaldehyde, anthracene-9-carbaldehyde, thioglycolic acid and carbon disulphide then with hydrazine hydrate analogues furnished a series of pyrazolo [3,4-d]

An efficient and rapid synthesis of coumarin derivatives was accomplished via reactions of 3‐(3‐(4‐methoxyphenyl)acryloyl)‐2H‐chromen‐2‐one (3) with different carbon nucleophiles such as ethyl acetoacetate, ethyl cyanoacetate, malononitrile, and ethyl benzoylacetate via conventional heating and microwave irradiation conditions and were used as source of pyran and pyridine derivatives bearing coumarin moiety 4–11. Compound 9a was condensed with different carbon electrophiles triethylorthoformate, phenylisothiocyanate, carbon disulfide, benzoylchloride, and acetylchloride that afforded the corresponding chromen derivatives 12–16. All the newly synthesized compounds were characterized by elemental and spectroscopic evidences. All of synthesized compounds were tested for in vitro cytotoxicity. The preliminary screening results showed that most of the compounds had moderate cytotoxic activity against HCT‐116 and MCF‐7 cell lines. Nevertheless, compound 10 exhibited potent activity against the two cell lines, which was comparable with the standard drug 5‐fluorouracil.

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A cyanoacetohydrazide derivative underwent a series of reactions with different nucleophilic reagents, such as hydrazine hydrate, p-chlorobenzaldehyde and salicylaldehyde, to give the condensation products. In addition, an arylidene malononitrile was reacted with different nitrogen nucleophiles, such as hydrazine hydrate, thiocarbohydrazide and cyanoacetohydrazide, to afford the hydrazine, hydrazone and pyridin-2-one derivatives, respectively. Furthermore, a pyridin-2-one derivative was reacted with different carbon electrophiles, such as carbon disulfide, p-chlorobenzaldehyde and acetic anhydride. The antimicrobial activities of some of the compounds were examined.

Chemistry General methods: All the solvents used were commercially purchased and distilled before use. Reactions were monitored by thin-layer chromatography (TLC) on silica gel plates (60F254), visualizing with ultraviolet light. Column chromatography was performed on silica gel (230-400 mesh) using distilled petroleum ether, ethyl acetate, dichloromethane, chloroform, and methanol. Infrared spectra (KBr) were recorded on FT-IR 5300 spectrophotometer and Perkin Elmer spectrum RXI FT-IR system (ν, cm-1). 1 H NMR spectra were recorded on Varian Gemini spectrophotometer (400 MHz)in DMSO-d6 or CDCl 3 as solvent. Proton chemical shifts (d) are relative to tetramethylsilane (TMS, d=0.00) as internal standard and expressed in ppm. Coupling constants J are given in hertz. Melting points were determined by using melting point apparatus and are uncorrected. MS spectra were obtained on a

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