Organobase-catalyzed three-component reactions for the synthesis of 4H-2-aminopyrans, condensed pyrans and polysubstituted benzenes.
Novel routes for the preparation of 2-amino-4H-pyran-3-carbonitrile 9, amino-arylbenzoic acid ester derivatives 13a,b, 2-aminotetrahydro-4H-chromene-3-carbonitrile 18, 3-amino-4-cyanotetrahydronaphthalene-2-carboxylic acid ester 26 and 4-amino-3,5-dicyanophthalic acid ester derivatives 37a-c were developed. The synthetic methods utilize one-pot reactions of acetylene carboxylic acid esters, α,β-unsaturated nitriles and/or active methylenenitriles in the presence of L-proline or DABCO. Plausible mechanisms are suggested for the formation of the products. Finally, these compounds were used for the efficient synthesis of 6-amino-5-cyanonicotinic acid ester derivatives 31a,b, ethyl 4-amino-5H-pyrano[2,3-d]pyrimidine-6-carboxylates 33a,b, 4-amino-6H-pyrrolo[3,4-g]quinazoline-9-carbonitrile 39, and 1,7-diamino-6-(N'-hydroxycarbamimidoyl)-3-oxo-5-phenyl-3H-isoindole-4-carboxylate (40).
Department of Chemistry, Faculty of Science; University of Kuwait, Safat, 13060, P.O. Box 5969, Kuwait.
Moustafa Sherief
MS
Moustafa
Department of Chemistry, Faculty of Science; University of Kuwait, Safat, 13060, P.O. Box 5969, Kuwait.
Saleh Mohammed
SM
Al-Mousawi
Department of Chemistry, Faculty of Science at Qena, South Valley University, P.O. Box 83523, Qena, Egypt.
Maghraby Ali
MA
Selim
Department of Chemistry, Faculty of Science at Qena, South Valley University, P.O. Box 83523, Qena, Egypt.
Ahmed Mohamed
AM
Mosallam
Department of Chemistry, Faculty of Science; University of Kuwait, Safat, 13060, P.O. Box 5969, Kuwait.
Mohamed Hilmy
MH
Elnagdi
DABCO; L-proline; aminopyranes; arylbenzoic acid; multicomponent; tetrahydronaphthalene; three-component reaction