9+9+9Synthesis of N,N'-bis(4-methyloxazol-5-yl)-urea as the key building block of 1,3-bis(4-methyloxazol-5-yl)xanthine towards an improved bronchodilator

986-9884-Methyloxazole-5-carboxylic acid <b style="mso-bidi-font-weight: normal">2 is converted to 4-methyloxazol-5-yl carboxazide 3 in a one-pot reaction with ethyl chloroformate and triethylamine in cold followed by treatment with sodium azide. 3 is transformed to 4-methyloxazol-5-yl isocyanate 4 by heating in dry benzene. 4, on reaction with aqueous sodium hydroxide in the presence of benzyltriethylammonium chloride and dichloromethane furnish N,N'-bis(4-methyloxazol-5-yl)urea <b style="mso-bidi-font-weight: normal">5, as the key building block of the theophylline analogue, 1,3-bis(4- methyloxazol-5-yl)xanthine, a possible improved bronchodialator. 13C NMR spectral intricacies of the oxazole ring system as an electron withdrawing unit have been discussed.</span

Studies on the crystal growth of rice bran wax in a hexane medium

Rice bran oil (RBO) is well known for its high wax content (2-4 %). A good separation of waxes must be ensured through the formation of crystals that can be removed with a minimal retention of oil to maintain high yields of refined oil. In the present study, the form and size distribution of RBO wax crystals were investigated using a laser diffraction technique. An attempt was made to study the effect of cooling on growth and size distribution of RBO wax crystals in hexane medium, and it showed that high cooling rate and low temperature induces the formation of a great number of small nuclei. In addition, experiments were performed to evaluate the effect on the growth of wax crystals of successive additions of gum and pure TG to the medium. The entire experiment was designed to optimize the temperature and incubation time of wax crystallization to facilitate the efficient separation of wax from crude RBO-hexane miscella using membrane technology

Thermally induced oxidative trimerization of benzimidazole by copper(II) chloride in the solid state

Benzimidazolium trichlorocuprate (II) undergoes a redox reaction in the solid state at elevated temperature (&#8764;240°C) to produce the cyclic trimer of benzimidazole and cuprous chloride. The trimer has been characterized by IR, NMR and Mass spectroscopy. It has also been synthesized in lower yield by heating the mixtures of CuCl2 and benzimidazole in different ratios or heating other compounds of CuCl2 and benzimidazole. The absorption, emission, and excitation spectra of the trimer in two different solvents (TFA and DMSO) and a comparison of these results with those of benzimidazole are presented here

Comparative study on treatment of kitchen-sink wastewater using single and multichannel ceramic membrane

A comparative study was conducted to explore the potential of ceramic microfiltration membrane alone and in combination with different physicochemical treatments, viz. biotreatment and adsorption using kitchen-sink wastewater. Cross-flow microfiltration (CMF) studies were carried out with tubular ceramic membrane in single channel and multichannel configuration. Biotreatment was studied using activated sludge process and adsorptive treatments were studied using a biosorbent prepared from the dried roots of Eichhornia crassipes, an aquatic weed which is abundantly grown in polluted water. The study showed better performance of 19 channel ceramic membrane compared to the single channel membrane in terms of the permeate quality, viz. BOD, COD, turbidity, TSS etc., as well as, permeate flux. Microfiltration of the adsorbent treated feed appeared to be most promising in comparison with the other feeds wherein, about 98% removal of BOD and 99% removal of COD were obtained. The quality of the treated water was found to be fit for use in horticulture, irrigation, etc