effective methodologies for efficient preparation of semicarbazones from aldehydes or ketones via milling and the subsequent regeneration of the parent carbonyls by gaseous nitrogen dioxide are described under solid-solid and gas-solid reaction conditions, respectively. these methods are fast, simple and environmentally benign which do not require the use of any auxiliaries such as catalysts or...

silica-bonded n-propyltriethylene-tetramine (sbnptt) was found as an efficient solid base for the synthesis of 2-amino-5-oxo-5,6,7,8-tetrahydro-4h-chromenes. chromene derivatives were obtained via the three-component condensation reaction of aromatic aldehydes, malononitrile, and dimedone at 80 oc under solvent-free conditions. the heterogeneous solid base showed much the same efficiency when u...

Effective conversion of lignocellulosic material as renewable energy source has significant reflection on economic and environmental impact. Diluted acid hydrolysis at optimal condition was used to liberate fermentable sugar. The sorghum stalks, the alkali pretreatment of biomass and hydrolysis in diluted hydrochloric acid were investigated. The hydrolysis reaction was carried out in a 5L react...

Effective methodologies for efficient preparation of semicarbazones from aldehydes or ketones via milling and the subsequent regeneration of the parent carbonyls by gaseous nitrogen dioxide are described under solid-solid and gas-solid reaction conditions, respectively. These methods are fast, simple and environmentally benign which do not require the use of any auxiliaries such as catalyst...

 phenytoine derivatives were synthesized , via the  pinacol condensation  with the  reaction of 1,3- diphenyl- propane- 1,3- dione (benzyl) analogs with urea or thiourea in presence of slica gel and solid KOH as Solid phase catalyst  in the mortar / pestle at room temperatures. The reaction was completed at short reaction times (approximately 15min) and pure products were obtained with high yie...

a basic alumina-spinel low cement castable (lcc) composed of sintered bauxite, reactive alumina, calcined alumina, calcined magnesia, microsilica, and high alumina refractory cement was prepared (castable a) to which 5% sodium hexa-meta phosphate was later added (castable b) to prepare samples for heat treatment at 110ºc, 900ºc, and 1400ºc. bulk density (bd), apparent porosity (ap), and cold cr...

the direct sulfation of three high purity iranian limestones and one precipitated calcium carbonate from different sources, containing more than 97 % caco3, were studied in a specially designed fixed bed reactor under atmospheric pressure, in the presence of excess co2 to prevent decomposition of caco3. experiments were carried out over a range of particle sizes from 1.6-2.5  mm at four tempera...

the nanopowders of sno2, casno3 and ca2sno4 in the size rang of 5-70 nm have been prepared using solid-state reaction technique. the technique is convenient and inexpensive in comparison to the conventional routes of compound prepared and processing where, many steps of mixing and annealing are involved. formation of resultant compounds was explained on the basis of reaction taken place between...