ZrOCl2.8H2O as a green and efficient catalyst for the expeditious synthesis of substituted 3-arylpyrimido[4,5-c]pyridazines in water

Abstract

A new and simple synthetic methodology for the preparation of 3-arylpyrimido [4,5-c]pyridazine-5,7(6H,8H)-diones and 3-aryl-5-oxo-7-thioxo-7,8-dihydropyrimido[4,5-c]pyridazin-5(6H)-ones by a one-pot three component reaction of barbituric acid or thiobarbituric acid with arylglyoxals in the presence of catalytic amount of ZrOCl2•8H2O as green Lewis acid and hydrazine hydrate at ambient temperature in water was reported. All of these pyrimidopyridazines derivatives have one clustered water molecule in their molecular structure. The use of ZrOCl2•8H2O catalyst is feasible because of its easy availability, convenient handling, high stability, simple recovery, reusability, good activity and ecofriendly.

Synthesis of ethyl-3-amino-1-aryl-1H-benzo[f]chromeme-2-carboxylate derivatives promoted by DMAP

“…In continuation of our efforts toward the development of greener methodologies, [32][33][34][35][36][37][38] we report here in a simple, clean, and environmentally friendly process for the synthesis of ethyl-3-amino-1-aryl-1H-benzo[f]chromene-2-carboxylate derivatives by reaction of various aromatic aldehydes with malononitrile or ethyl cyanoacetate and phenols (α-naphthol or β-naphthol ) in the presence DMAP, as catalyst and co-solvent (Scheme 1).…”

Green and efficient one-pot three-component synthesis of novel drug-like furo[2,3-d]pyrimidines as potential active site inhibitors and putative allosteric hotspots modulators of both SARS-CoV-2 MPro and PLPro

“…Zirconium IV oxychloride octahydrate (ZrOCl 2 •8H 2 O), as an available, low-cost, easy handling, and moisture-stable catalyst with highly coordinating ability, has attracted the attention in the organic synthetic community. [23] In the past two decades, the mentioned green catalyst has been used frequently in various organic transformations, especially heterocyclic ones, including syntheses of 4 H -chromenes, [24] pyrimido [4] , [5] , [6] , [7] , [8] , [9] , [10] , [11] , [12] , [13] , [14] , [15] , [16] , [17] , [18] , [19] , [20] , [21] , [22] , [23] , [24] , [25] , [26] , [27] , [28] , [29] , [30] , [31] , [32] , [33] , [34] , [35] , [36] , [37] , [38] , [39] , [40] , [41] , [42] , [43] , [44] , [45] , [46] , [47] , [48] , [49] , [50] , [51] , [52] , [53] , [54] , [55] , [56] , [57] pyrimidinones, [25] dibenzo[ b , i ]xanthene-tetraones, [26] , [1] , [3] oxazino [5] , [6] ,…”