The synthesis of novel derivatives of pyrazole-3-carboxylate (3-5) from methyl 4-(benzofuran-2-yl)-2,4-dioxobutanoate (1) is reported. Synthesis of substituted 1,3,4-oxadiazoles (7-11) and 5-amino pyrazole-4-carboxylate (12) derivatives starting from the 5-(benzofuran-2-yl)-1-phenyl-1H-pyrazole-3-carbohydrazide (6) are also described. Twelve new compounds were synthesized and their identities have been established on the basis of elemental and spectroscopic analysis such as IR, 1H NMR, 13C NMR, Mass Spectra. The compounds were also screened for their antibacterial and antifungal activities against Gram-positive, Gram-negative bacteria and a fungus.
A highly efficient, simple and rapid method for the preparation of various 2-aminobenzoxazoles and other benzoxazole derivatives using a catalytic amount of poly (ethylene glycol)-bound sulphonic acid (PEG-SO3H) is described. PEG-SO3H is found to be economical and reusable catalyst with low catalytic loading. The percentage yield was found to be satisfactory, experimental set-up and purification of final products is facile and easy.
Synthesis of two series of 1,2- and 1,4-bis(thioureido)benzene derivatives was accomplished by the treatment of corresponding alkanoyl/aroyl chlorides with potassium thiocyanate in dry acetone to afford the respective isothiocyanates as intermediates. The latter were treated in situ with 1,2- and 1,4-diaminobenzene, respectively, to afford the title compounds in high yields. A total of sixteen new compounds are reported herein. The structures of the products were confirmed by spectroscopic techniques (IR, 1H and 13C NMR, mass spectrometry), elemental analysis and in case of 1d, by X-ray diffraction technique. All the synthesized compounds were also subjected to antibacterial bioevaluation against ten different Gram-positive and Gram-negative bacterial strains using levofloxacin as the standard drug and were shown to possess promising activities.
Nano-materials are considered as suitable heterogeneous catalysts for many organic reactions. Herein oxidized carbon nanotube (SWCNTs-COOH) has been reported as a heterogeneous catalyst, for protection of carbonyl groups as hydrazones in EtOH at 80 °C. The reactions proceed smoothly with good to excellent yields, and the SWCNTs-COOH used can be recycled.
This article reports on the development and refinement of a questionnaire for first-year Chemistry students. Three subscales were probed, namely affective attitudes, perceptions towards tutor effectiveness and outcomes achieved.
Functionalizing pentacyclo[5.4.0.02,6.03,10.05,9]undecane-8-11-one and 1-phenyl-pentacyclo[5.4.0.02,6.03,10.05,9]undecane-8-11-one can be easily accomplished by using the alcohols of various alkynes and alkenes. Generally the synthesis of terminal alkyne and cyclic alkene ketal derivatives were performed fairly easily. Synthesis of the terminal alkenes provided some difficulties. Reduction of the alkyne ketal derivatives using Pd/CaCO3 has been demonstrated to forma mixture containing the desired alkene ketal derivatives.