Functionalized indeno[1,2-b]chromene derivatives have been synthesized via condensation reaction of 1H-indene-1,3(2H)-dione with benzaldehyde and cyclization with 2-hydroxynaphthalene-1,4-dione in the presence of a catalytic amount of triethylamine (Et3N) in EtOH at room temperature. It was observed that benzaldehyde bearing electron donating group gave high yield of product, whereas, benzaldeh...

The reaction of 6-formyl-7-hydroxy-5-methoxy-2-methylbenzopyran-4-one with dimethyl acetylenedicarboxylate and benzil gave the respective 4H,6H-pyrano[3,2-g]chromene and imidazolylbenzopyran derivatives. Treatment of the imidazolylbenzopyran with hydrazine hydrate or hydroxylammonium chloride yielded imidazolylpyrazolylor imidazolylisoxazolylbenzenes, while the alkaline hydrolysis of imidazolyl...

Bismuth triflate (Bi(OTf)3) is identified as an efficient catalyst for the direct addition of isocyanides to 2H-chromene acetals. The large scope of isocyanides and chromene acetals makes them suitable substrates in this catalytic system. By this synthetic strategy, a polyfunctional molecular scaffold, 2-carboxamide-2H-chromenes could be prepared efficiently in one step up to 95% yield. In addi...

Chalcone and chromene motifs are synthetic or naturally occurring scaffolds with significant cytotoxic profile. Two types of novel regioisomeric chromene-chalcone hybrids, namely 1-(6-chloro or 6-methoxy-2H-chromen-3-yl)-3-phenylprop-2-en-1-one (Type A) and 3-(6-chloro or 6-methoxy-2H-chromen-3-yl)-1-phenylprop-2-en-1-one (Type B), both with different substituents on the phenyl ring attached to...

In the title compound, C24H14Cl2N2O2S, the 2H-chromene ring system is approximately planar, with a maximum deviation of 0.025 (2) Å. The thia-zole ring is almost planar, with an r.m.s. deviation of 0.0022 Å, and makes a dihedral angle of 58.52 (7)° with the chromene ring system. The chromene ring system is inclined at angles of 58.3 (1) and 55.39 (9)° with respect to the two chloro-phenyl rings...

In this work, the interaction of protonated amino acids with a chromene bearing a fused 18-crown-6 ether moiety was studied by UV-vis and NMR spectroscopy. Initial closed forms of the chromene form monotopic 1 : 1 complexes, the ammonium group being localized inside the crown ether cavity. UV-irradiation leads to transformation of the ring-closed species into the ring-opened form. Depending on ...

  We wish to report a mild and efficient one-pot three-component reaction of an aryl aldehyde, malononitrile and barbituric acid or 4-hydroxycoumarinfor the synthesis ofpyrano[2,3-d]pyrimidine and dihydropyrano[c]chromene derivatives in the presence o...

A novel catalytic synthesis of 3,3'-(arylmethylene)-bis-(4-hydroxy-2H-chromene-2-one) derivatives from a tandem condensation reaction of 4-hydroxycoumarin and aromatic aldehydes has been developed. The reaction occurs in water in the presence of Melamine trisulfonic acid as catalyst to give the corresponding products in good to high yields. This green approach has several advantages such as sho...

2-Amino-5,10-dioxo-4-aryl-5,10-dihydro-4H-benzo[g]chromene-3-carbonitrile derivatives are obtained in excellent yields with a simple and efficient procedure.This reaction can occur using electrocatalytic multicomponent chain transformation of aryl aldehydes, 2-hydroxynaphthalene-1,4-dione and malononitrile under neutral and mild conditions. Moreover, electrolysis is done in CH3CN as solvent, Te...