sulphuric acid adsorbed on silica gel is a practical and useful catalyst for acetylation of varius alcohols, phenols and amines.

a simple extremely fast and efficient approach for the synthesis of substituted indazole ingood to excellent yield catalyzed by using silica sulfuric acid (ssa) in dmso solvent at roomtemperature. this is solid state reaction have been attracting the synthetic organic chemist asthey provided enhance reaction rates, less environmental pollution, greater selectivity, cleanerproducts and manipulat...

Sulphuric acid adsorbed on silica gel is a practical and useful catalyst for acetylation of varius alcohols, Phenols and amines.

in cases of overdose and identification of the actual barbiturate concerned may be impossible because of the closely similar Rf values of this group. Jackson (1960) described treatment with hot sulphuric acid before paper chromatography to distinguish between barbiturates of similar chromatographic mobility. The inert nature of the silica gel supporting medium used in thin-layer separations ena...

the aim of this study was to evaluate the effects of chemical treatments including urea (5%), ammonia (3.5%), calcium hydroxide (4%), sodium hydroxide (5%), sulphuric acid (5%) and hydrogen peroxide (5%) on ph, dm solubility, lignin, silica, phenolic compounds, cellulose and hemicellulose stucture and ruminal degradability of rice straw. after processing, the treated straw was ensiled for 1 mon...

We have performed a series of simulations with an aerosol dynamics box model to study the connection between new particle formation and sulphuric acid concentration. For nucleation either activation mechanism with a linear dependence on the sulphuric acid concentration, kinetic mechanism with a squared dependence on the sulphuric acid concentration or ternary H2O-H2SO4-NH3 nucleation was assume...

Sulphuric acid is a key component in atmospheric new particle formation. However, sulphuric acid alone does not form stable enough clusters to initiate particle formation in atmospheric conditions. Strong bases, such as amines, have been suggested to stabilize sulphuric acid clusters and thus participate in particle formation. We modelled the formation rate of clusters with two sulphuric acid a...

A simple, precise and rapid high-performance thin-layer chromatographic method has been developed for the estimation of phyllanthin (1) and hypophyllanthin (2), the important lignans of Phyllanthus species, especially Phyllanthus amarus. Separation of 1 and 2 was carried out on silica gel 60 F254 layers eluted with hexane:acetone:ethyl acetate (74:12:8), and the analytes were visualised through...