6 research outputs found
Simple and Green Adipic Acid Synthesis from Cyclohexanone and/or Cyclohexanol Oxidation with Efficient (NH4)xHyMzPMo12O40 (M: Fe, Co, Ni) Catalysts
The oxidation of cyclohexanone and/or cyclohexanol to adipic acid (AA) was performed at 90 °C with a reaction time of 20 h, in the presence of H2O2 as oxidant and transition metal substituted ammonia polyoxometalates of formula, (NH4)xHyMzPMo12O40 (M: Fe, Co, or Ni, and x = 2.5 or 2.28) as catalysts. The catalytic results showed that the AA yield is sensitive to the transition metal nature and to the reaction conditions (sample weight and substrate amount). The (NH4)2.29H0.39Co0.16PMo12O40 was found to be the better catalytic system toward AA synthesis from cyclohexanone oxidation, with 40% of AA yield
Cyclohexanone Oxidation over H3PMo12O40 Heteropolyacid via Two Activation Modes Microwave Irradiation and Conventional Method
The adipic acid (AA), important precursor for Nylon production, was synthesized from cyclohexanoneoxidation by two ways, microwaves irradiation and conventional method (under reflux) using H3PMo12O40 heteropolyacid as catalyst in the presence of hydrogen peroxide. In the order to increase the AA yield, several parameters as cyclohexanone/catalyst ratio, H2O2 concentration, solvent nature (H2O, CH3CO2H, and CH3OH, CHCl3 and CH3CN) and cyclohexanol addition to cyclohexanone were examined. For both activation modes, the highest AA yields are of 26-28%. Whereas, with microwaves irradiation, the time gain is much more attractive 30 min compared to 20 h. Copyright © 2019 BCREC Group. All rights reserve
Synthesis of Substituted 1,4-Diazepines and 1,5-Benzodiazepines Using an Efficient Heteropolyacid-Catalyzed Procedure
An efficient and improved procedure for the synthesis of 1,4-diazepine and 1,5-benzodiazepine derivatives via the reaction of ketimine intermediates with aldehydes in the presence of Keggin-type heteropolyacids (HPAs) was developed. High yields and short reaction times were obtained for both electron-releasing and electron-withdrawing substituted 1,4-diazepine and 1,5-benzodiazepines derivatives
A Microwave-Assisted and Heteropolyacids-Catalysed Cyclocondensation Reaction for the Synthesis of 4(3H)-Quinazolinones
We have investigated a microwave–assisted synthesis of 4(3H)–quinazolinonesby condensation of anthranilic acid, orthoesters (or formic acid) and substituted anilines,using Keggin-type heteropolyacids (H3PW12O40·13H2O, H4SiW12O40·13H2O,H4SiMo12O40·13H2O or H3PMo12O40·13H2O) as catalysts. We found that the the use of H3PW12O40·13H2O acid coupled to microwave irradiation allows a solvent-free, rapid (~ 13min) and high-yielding reaction
Recyclable Keggin Heteropolyacids as an Environmentally Benign Catalyst for the Synthesis of New 2-Benzoylamino-N-phenyl-benzamide Derivatives under Microwave Irradiations at Solvent-Free Conditions and the Evaluation of Biological Activity
2-Benzoylamino-N-phenyl-benzamide derivatives (5a–h) were prepared from 2-phenyl-3,1-(4H)-benzoxazin-4-one 3 and substituted anilines 4a–h in the presence of a Keggin-type heteropolyacids series (H3PW12O40·13H2O; H4SiW12O40·13H2O; H4SiMo12O40·13H2O; and H3PMo12O40·13H2O) as catalysts without solvent and under microwave irradiation. We found that the use of H3PW12O40·13H2O acid coupled to microwave irradiation allowed obtaining a high-yielding reaction with a short time. The compound structures were established by 1H-NMR and 13C-NMR. The antibacterial and antifungal activities of the synthesized compounds exhibited an inhibition of the growth of bacteria and fungi