The solid–solid reactions of electron-donor compounds, such as: barbituric acid (1a), thiobarbituric acid (1b), 1,3-dimethyl barbituric acid (1c), phenol (1d) and resorcinol (1e) with diazotized o-nitroaniline (3), m-nitroaniline (4) and p-nitroaniline (5) catalyzed by p-toluenesulfonic acid (2) afford azo dyes by grinding in good yields. This new method totally avoids the use of inorganic acid...

a simple, efficient and clean procedure has been developed for the cleavage of imines c=n bond. deprotection of imines to their parent carbonyl and amine compounds was achieved using p-toluenesulfonic acid in the solid state condition at 25-45 ˚c. the salient features of this methodology are shorter reaction times, cheap processing, high yields of product and easy availability of the catalyst. ...

the esterification of free fatty acids (ffa) with methanol is studied using sulfonated porous carbon (spc) as catalyst. in compare to the amorphous sugar catalyst and protonated nafion, the proposed catalyst shows stability and high efficient performance in biodiesel production. the highest initial rate of oleic acid conversion is obtained at catalyst loading of 1 mmol h+ and mole ratio of meoh...

Silica-bonded n-propyldiethylenetriamine sulfamic acid (SBPDSA) was found as an efficient solid acid for the synthesis of coumarins. Coumarin derivatives were obtained via the Pechmann condensation reaction of phenols and β-keto-esters at 80 oC under solvent-free conditions. Also, biscoumarins were obtained via the condensation of aldehydes and 4-hydroxycoumarin in water at reflux conditions. T...

abstract effect of different concentrations of salicylic acid on postharvest life of kiwifruit (actinidia deliciosa) cultivar hayward at 0 ±.5 °c and 90-95% rh was studied. fruits were treated with salicylic acid (0, 1 and 2 mmol/l-1) and stored at 0±.5°c for 16 weeks. fruit quality attributes assessment including firmness, total acidity, soluble solid content, ascorbic acid, antioxidant activi...

Silica-bonded n-propyldiethylenetriamine sulfamic acid (SBPDSA) was found as an efficient solid acid for the synthesis of coumarins. Coumarin derivatives were obtained via the Pechmann condensation reaction of phenols and β-keto-esters at 80 oC under solvent-free conditions. Also, biscoumarins were obtained via the condensation of aldehydes and 4-hydroxycoumarin in water at reflux conditions. T...

silica sulfuric acid is employed as solid acid catalyst for the clean and less hazardousprotection of carbonyl compounds as 2,4-dinitrophenylhydrazone under solvent-free conditions.

Bamboo is one of the important biopolymers which is used in chemistry. In this work, for the first time, a solid acid catalyst from bamboo was prepared from the reaction of sawdust bamboo and chlorosulfonic acid. Relevant properties of catalyst were investigated by FT-IR, XRD, SEM and TGA. The sulfonated bamboo (bamboo-SO3H) with several acid functional groups was utilized as highly ...

In this research, the chemical recycling of terephthalic acid from PET waste by using nano Fe3O4@Py-APTS as solid support was reported. The performance of organically modified nano magnetic was examined in detail and the results were compared with unsupported reactions as the model. By using the solid support, the required time for complete glycolysis, consumption of solvent and catalyst, decre...