Ultrasound mediated, iodine catalyzed green synthesis of novel 2-amino-3-cyano-4H-pyran derivatives

Abstract

An efficient synthesis of a novel series of twelve substituted 2-amino-3-cyano-4H-pyran derivatives was achieved by a one-pot three-component cyclocondensation reaction of heteroaryl aldehydes, malononitrile and active methylene compounds catalyzed by iodine in aqueous medium under ultrasound irradiation. In comparison with conventional methods, our protocol is convenient and offers several advantages, such as shorter reaction time, higher yields, milder conditions and environmental friendliness. We have herein successfully demonstrated the synergistic outcome of multi-component reaction (MCR) and sonication to offer a facile route for the design of these derivatives.

Uses of ethyl benzoylacetate for the synthesis of thiophene, thiazole, pyridine, and pyran derivatives with antitumor activities

“…Due to such great benefits of MCRs, the synthesis of many heterocyclic compounds was carried out applying such MCRs . On the other hand, many pharmaceutical drugs contained 4‐ H pyran moieties; this encouraged us to synthesize 4‐ H pyran derivatives through the MCRs of compound 14a. Therefore, the reaction of compound 14a with either of the aromatic aldehydes 26a, 26b, or 26c and malononitrile (2) in 1,4‐dioxane containing triethylamine gave the pyran derivatives 27a‐c, respectively.…”

Synthesis of Novel Heterocyclic Compounds Incorporate 4,5,6,7-Tetrahydrobenzo[<i>b</i>]thiophene Together with Their Cytotoxic Evaluations

“…22) They are also applicable to the synthesis of heterocyclic systems. 23) It is quite remarkable that many topselling pharmaceuticals containing 4-H pyran derivatives [24][25][26][27][28] which encouraged us to synthesize the 4-H pyran and 4-H pyridine derivatives through the multi-component reactions of compound 19. Thus, compound 19 underwent the MCR of malononitrile and any of benzaldehyde, 4-chlorobenzaldehyde or 4-methoxybenzaldehyde in ethanolic triethylamine solution to give the pyran derivatives 20a-c, respectively.…”

Uses of Cyclohexan-1,4-dione for the Synthesis of 2-Amino-4,5-dihydrobenzo[<i>b</i>]thiophen-6(7<i>H</i>)-one Derivatives with Anti-proliferative and Pim-1 Kinase Activities

“…33) They are also applicable to the synthesis of heterocyclic systems. 34) It is quite remarkable that many top-selling pharmaceuticals contains "4-H pyran" derivatives [35][36][37][38][39] this encouraged us to synthesis 4-H pyran derivative through the multi-component reactions of compounds 3a-c. Thus, the reaction of any of compounds 3a-c with any of benzaldehyde (6a), 4-chlorobenzaldehyde (6b) or 4-nitrobenzaldehyde (6c) and either of malononitrile (7a) or ethyl cyanoacetate (7b) gave the 5,9-dihydro-4H-thieno[2,3-f ] chromene derivatives 9a-r, respectively (Chart 2).…”