Luciana Morais Canavieiraa, Edikarlos Macedo Brasilb , Thiago de Melo e Silvac, Rosivaldo dos Santos Borgesd José Rogério Araújo Silvac* Jerônimo Lameiraac Paul V. Bernhardte, Craig M. Williamse & Cláudio Nahum Alvesc* a Programa Pós-Graduação em Biotecnologia, Instituto Ciências Biológicas, Universidade Federal do Pará, Belém, Brazilb Peptide Science Laboratory, School of Chemistry and Physics...

Although salicylaldehyde azine (3) was reported in 1985 as the single product of the reaction of ethyl 2-oxo-2H-chromene-3-carboxylate (1) with hydrazine hydrate, we identified another main reaction product, besides 3, which was identified as malono-hydrazide (4). In the last two decades, however, some articles have claimed that this reaction afforded exclusively hydrazide 2 and they have repo...

In the asymmetric unit of the title compound, C(16)H(11)FO(5)S, the 2H-chromene ring is essentially planar, with a maximum deviation of 0.040 (2) Å. The dihedral angle between the 2H-chromene ring and the 4-fluoro-phenyl ring is 2.17 (8)°. One of the sulfonamide O atoms is approximately coplanar with the benzene ring [C-C-S-O torsion angle = 166.00 (14)°], whereas the other O atom lies well bel...

The synthesis of 2-benzylamino-8-methoxy-4H-chromene-3-carbonitriles 7(a-e) has been realized in four steps, via reductive amination from the 2-amino-8-methoxy-4H-chromene-3-carbonitrile 4 as key intermediate platform with para- and meta-substituted benzaldehydes 5(a-e), good overall yields. physicochemical properties also their aldimines 6(a-e) precursors have determined using Swiss ADME serve...

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...

na2so4 as an inexpensive and effective catalyst has provided a green protocol for the synthesis of tetrahydrobenzo[b]pyran, pyrano[2,3-d]pyrimidinone and dihydropyrano[3,2c]chromene derivatives from the three-component domino reaction of aromatic aldehydes and malononitrile with 4-hydroxycoumarin/ dimedone/ barbituric acid in ethanol/water as a mixture of solvent that, this mixture entirely is ...