Synthesis of polyheterocyclic compounds derived from 6-amino- 4-aryl-2-r-4h-furo[2,3-b]pyran-5-carbonitriles

Abstract

Keywords:6-amino-4-aryl-2-R-4H-furo[2,3-b]pyran-5-carbonitriles, 4-aryl-6-ethoxy-2-R-furo-[2,3-b]pyridine-5-carbonitriles, ethyl acetoacetate, ethyl esters of 5-amino-4-aryl-7-methyl-2-R-4H-1,9-dioxa-8-aza-cyclopenta[b]naphthalene-6-carboxylic acids, recyclization.6-Amino-4-aryl-2-R-4H-furo[2,3-b]pyran-5-carbonitriles 1-3 are an important class of heterocyclic compounds, which hold considerable interest in light of their various chemical transformations and practical applications [1]. These bifunctional compounds, containing vicinal nitrile and amino groups, are promising starting materials for obtaining previously not readily available fused heterocyclic systems. The synthesis of carbonitriles 1-3 employs the base-catalyzed Michael condensation of 5-aryl-3-arylmethylene-3H-furan-2-ones with malononitrile [2].The reaction of carbonitriles 1-3 with a C-nucleophile, namely, ethyl acetoacetate, upon heating in ethanol at reflux in the presence of catalytic amounts of triethylamine gives ethyl esters of 5-amino-4-aryl-7-methyl-2-R-4H-1,9-dioxa-8-azacyclopenta[b]naphthalene-6-carboxylic acids 4-6. O O Ar NH 2 R CN Me O O EtO Et 3 N O N O R Ar NH 2Me CO 2 Et 4-6 1-3 + 1, 4 R = Ph; 2, 5 R = 4-MeC 6 H 4 , 3, 6 R = 4-MeOC 6 H 4 ; 1-6 Ar = 2-ClC 6 H 4

Synthesis of Compounds of the Pyrimidine Series Based on the Reactions of 3-Arylmethylidenefuran-2(3H)-ones with N,N-Binucleophilic Reagents

“…As a substrate, 3-arylmethylidenefuran-2(3 H )-ones have some advantages. They can be easily obtained, and they are convenient, cost-effective substrates for the synthesis of various hard-to-reach heterocyclic, spirocyclic, and polycyclic compounds [ 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 ]. 3-Arylmethylidenefuran-2(3 H )-ones are substances which combine the properties of internal esters and α,β-unsaturated carbonyl compounds, and they are able to react with substances with mobile hydrogen atoms.…”