A Green and Efficient Process for the Synthesis of Benzothiazinones using Phosphate Fertilizers MAP, DAP and TSP as Heterogeneous Catalysts

Abstract

The aim of this work is to demonstrate the efficiency of the phosphate fertilizers monoammonium phosphate (MAP), di-ammonium phosphate (DAP), and triple-super phosphate (TSP) as a“green” heterogeneous catalyst for the synthesis of 2-aryl-2H-benzo[b][1,4]thiazin-3(4H)-ones via the CS and C-N coupling process of gem-dicyano epoxide with α-aminothiophenol. To optimize the reactionconditions, the synthesis was conducted with a range of solvents, catalyst amounts, and particle sizes ofthe catalyst. Also, the recyclability potential of the catalysts was confirmed by using the recycled catalyst.