Microwave assisted synthesis of 2-amino-6-methoxy-4H-benzo[h]chromene derivatives

Abstract

A convenient and efficient method using microwave assisted synthesis of 4H-benzo[h]chromenes (7 and 8), by the reaction of 4-methoxy-1-naphthol (1) with a mixture of aromatic aldehydes (2) and malononitrile (3) or ethyl cyanoacetate (5) and also, by the reaction of 4-methoxy-1-naphthol (1) with α-cyanocinnamonitriles (4) or ethyl α-cyanocinnamates (6) in ethanolic piperidine solution was examined. Structures of the newly synthesized compounds were established on the basis of spectral data, IR, 1 H NMR, 13 C NMR, 13 C NMR-DEPT and MS data. Benzochromenes Pyran derivativesMicrowave synthesis 4-Methoxy-1-naphthol α-Cyanocinnamonitriles Ethyl α-cyanocinnamates

Structural Characterization and Antimicrobial Activities of 7H-Benzo[h]chromeno[2,3-d]pyrimidine and 14H-Benzo[h]chromeno[3,2-e][1,2,4]triazolo[1,5-c] pyrimidine Derivatives

“…In continuation of the previous works [15,25,26,27,28,29,30,31,34,35,36,37], it seemed interesting to synthesize some new 7 H -benzo[ h ]chromeno[2,3- d ]-pyrimidine and 14 H -benzo-14 H -benzo[ h ]chromeno[3,2- e ][1,2,4]-triazolo[1,5- c ]pyrimidine derivatives and to appraise their antimicrobial activities. The structure-activity relationships (SAR) are discussed in this work to correlate between the substituent effects and the activities that aid in drug design.…”

“…2-Amino-4-(4-fluoro/chloro/bromophenyl)-6-methoxy-4 H -benzo[h]chromene-3-carbonitriles 4a – c , 2-ethoxymethyleneamino-4-(4-fluoro/chloro/bromophenyl)-6-methoxy-4 H -benzo[ h ]chromene-3-carbonitriles 5a – c and 9-amino-7-(4-fluoro/chloro/bromophenyl)-5-methoxy-8-imino-7 H -benzo[ h ]-chromeno[2,3- d ]pyrimidines 6a – c were prepared by reported methods ([34,35,36,37], [29,30,31] and [29,30,31], respectively).…”

Catalyst-Free Cascade Synthesis of Densely Functionalized Chromenes in Water

“…activation [19], microwave irradiation [20,21], ultrasound activation [22] and under ionic liquids [23], deep eutectic solvents [24], aqueous media [25][26][27][28] and under solvent-free catalyst free conditions [29,30]. Despite satisfactory results, most of these methods need to overcome from limitations such as harsh reaction conditions, tedious work-up and purification procedures, lack of substrate generality and thus, the development of an efficient environmental friendly protocol with more general applicability is of great importance from the synthetic organic and Green Chemistry viewpoint.…”

[AcMIm]Cl-Catalyzed One-Pot Multicomponent Synthesis of Pyran Chromene Derivatives

“…Over the decade, one-pot multicomponent synthesis of coumarin-fused pyran annulated 4 H -chromenes and pyran-fused 2-aminochromenes has attracted much attention due to their potential biological activities, such as antibacterial, 8 9 anticoagulant, 10 antioxidant, 11 antimicrobial, 12 13 acetylcholinesterase (AChE) inhibitory, 14 anti-rheumatic, 15 antiproliferative, 16 17 anti-inflammatory, 18 anticancer, 19 antitumor, 20 suppression of influenza virus sialidases, 21 etc. Some important bioactive coumarin-fused 4 H -chromenes and pyrano-fused 2-aminochromenes are given in Fig.…”