Silica-bonded N-propylpiperazine sodium n-propionate as recyclable catalyst for synthesis of 4H-pyran derivatives

Synthesis of spirooxindole pyrimidines catalyzed by silica-bonded N-propyltriethylenetetramine as a recyclable solid base catalyst in aqueous medium

“…Proposed mechanism for the synthesis of spiro derivative 4 was described in Scheme 2 [45,64,72]. The process represents a typical cascade reaction in which the isatin 1 first condenses with malononitrile (2a) to afford isatylidene malononitrile derivative 5 in the presence of SBNPTT in water.…”

“…Along the line of our studies in application of heterogeneous catalysts in chemical transformations [63][64][65][66][67][68][69][70][71][72][73] herein, we wish to describe the application of SBNPTT as a solid base catalyst for the synthesis of spirooxindole derivatives.…”

Agar: a novel, efficient, and biodegradable catalyst for the one-pot three-component and green synthesis of 2,3-dihydroquinazolin-4(1H)-one, 4H-pyrimidobenzothiazole and 2-aminobenzothiazolomethylnaphthol derivatives

“…The progress of the reaction was monitored by TLC. After [1,3]benzothiazole derivatives in the presence of agar as the catalyst completion of the reaction, the reaction mixture was cooled to room temperature, and diluted with water. The mixture was filtered and then washed with distilled water for separation of the product.…”

“…The development of environmentally benign, efficient, and economical methods for the synthesis of biologically interesting compounds remains a significant challenge in synthetic chemistry [1,2]. One-pot multi-component reaction strategies (MCRs) are believed to exhibit negative activation volumes owing to the condensation of several molecules into a single reactive intermediate and product because of their convergence, productivity, facile performance and high yields [3].…”

“…Recently, Lindsley and coworkers observed the metabotropic glutamate receptor (mGluR) properties of this class of compounds [8]. Thus, developing versatile approaches to the synthesis of 2,3-dihydroquinazolin-4(1H)-ones, 4H-pyrimido [2,1-b] [1,3]benzothiazoles and 1-((benzo[d]thiazol-2-ylamino)(aryl)-methyl)naphthalen-2-ols still remains a highly desired goal in organic synthesis, because of their potential biological and pharmaceutical activities. There are many reports on the synthesis of dihydroquinazolin-4(1H)-ones, 4H-pyrimido [2,1-b] [1,3]benzothiazole and 1-((benzo[d]thiazol-2-ylamino)(aryl)-methyl)naphthalen-2-ol derivatives by threecomponent reaction of aldehydes, 2-aminobenzothiazole and isatoic anhydride or bnaphthol or ethyl/methyl acetoacetate in the presence of heterogeneous catalysts, for example Fe 3 O 4 nanoparticles [9], copolymer-p-TSA [10], p-TSA-NaHSO 3 [11], silica sulfuric acid [12], gallium(III) triflate [13], Amberlyst-15 [14], KAl(SOO(alum) [12], montmorillonite K-10 [15], zinc(II) perfluorooctanoate [16], the ionic liquids 1-butyl-3-methylimidazolium bromide[bmim]Br or [bmim]PF6 [17,18], [Al(H 2 PO 4 ) 3 ] [22], tetramethylguanidinium trifluoroacetate (TMGT) [19], silica sulfuric acid (SSA) [20], and sulfamic acid (SA) [21].…”