An efficient multi-component synthesis of (2-amino-3-cyano-4H-chromen-4-yl) phosphonic acid diethyl ester

PMDTA-catalyzed multicomponent synthesis and biological activity of 2-amino-4H-chromenes containing a phosphonate or phosphine oxide moiety

“…10 Most procedures utilizing the above synthesis route were carried out in the presence of both a catalyst and a solvent. Diethylamine, 11 dibutylamine, 7 triethylamine, 12 dimethylaminopyridine, 13 imidazole, 14 ethylenediamine diacetate, 15 lithium hydroxide, 16 potassium phosphate, 17 magnesium oxide 18 or indium chloride 19 were tried out in ethanol, and iron oxide, 20 iodine 21 or β-cyclodextrin 22 in water. Water may be considered as a green solvent; however, it requires an additional extraction step during the reaction workup.…”

Aqueous microwave-assisted DMAP catalyzed synthesis of β-phosphonomalonates and 2-amino-4H-chromen-4-ylphosphonates via a domino Knoevenagel-phospha-Michael reaction

“…Variety of catalysts as claysupported heteropolyacid [12], g-Fe 2 O 3 -pyridine based catalyst [13], 3-aminopropylated silica gel [14], sodium stearate [15], HClO 4 eSiO 2 [16], Fe-doped single walled carbon nanotubes [17], lanthanum(III) triflate supported on nanomagnetic g-Fe 2 O 3 [18], polystyrene-supported DABCO [19] pyridine-grafted graphene oxide [20], quaternary ammonium salt [H-dabco][AcO] [21], di-n-butylamine [22], nanosized zinc oxide [23], Phosphomolybdic acid [24], have been employed for the synthesis of b-phosphonomalonates. Further, catalysts like nano-MgO [25], sulfochitosan encapsulated nano-Fe 3 O 4, [26] ionic liquid [Bmim]OH [27], PEG [28], potassium phosphate [29], b-cyclodextrin [30],…”