No abstract

This work presents a simple process for the preparation of Cobalt Orthophosphate (Co 3 (PO 4 ) 2 ), by modifying phosphate fertilizer mono-ammonium phosphate (MAP) by cobalt nitrate (Co(NO 3 ) 2 ). Co 3 (PO 4 ) 2 has been characterised using microscopic and spectroscopic methods namely X-ray diffraction (XRD), infrared spectroscopy (IR) and scanning electron microscopy (SEM). It is the first time that Co 3 (PO 4 ) 2 is used as a heterogeneous catalyst in the condensation between an aryl aldehyde, 4-hydroxycoumarin and malononitrile. The results show that Co 3 (PO 4 ) 2 is an effective catalyst for one-pot synthesis of 3,4-dihydropyrano [3, 2-c] chromene. The optimisation of each reaction parameter allows achieving excellent results in terms of time and yield. The application of Co 3 (PO 4 ) 2 as catalyst in the 3, 4-dihydropyrano [3, 2-c] chromene derivatives synthesis offers certain advantages such as shorter reaction time, simple treatment, furthermore, the catalyst possesses a great capacity for reutilization and therefore its application contributes to the development of green chemistry.[a] A.

The present work focused on developing a new protocol of the 1-(benzothiazolylamino) methyl-2-naphthol derivatives synthesis by condensation of three compounds, i.e. aromatic 2-naphthol, 2-aminobenzothiazole and aldehyde. Furthermore, this reaction was carried out in the presence of three heterogeneous phosphate catalysts: monoammonium phosphates (MAP), diammonium phosphate (DAP), and trisuperphosphate (TSP). Moreover, this method offered many advantages, such as: very high yields, shorter reaction times, and the catalysts, can be easily recovered and reused without any loss of their catalytic activities.  Copyright ©2019 BCREC Group. All rights reserved

The synthesis of quinoxaline derivatives were heterogeneously catalyzed by phosphate-based catalyst fertilizers, MAP, DAP, or TSP. The reaction affords the desired products in excellent yields at ambient temperature. A series of studies were conducted to investigate the effect of solvent reaction, its volume, and catalyst amount. A study of the recyclability of catalysts removed from the reaction mixture by simple filtration was also carried out to find that the three phosphate-based catalysts retain their catalytic activities up to six cycles.