Six N-substituted-phenyl 4-oxo-4H-chromene-3-carboxamides, namely N-(2-nitro-phen-yl)-4-oxo-4H-chromene-3-carboxamide, C16H10N2O5 (2b), N-(3-meth-oxy-phen-yl)-4-oxo-4H-chromene-3-carboxamide, C17H13NO4, (3a), N-(3-bromo-phen-yl)-4-oxo-4H-chromene-3-carboxamide, C16H10BrNO3, (3b), N-(4-methoxy-phen-yl)-4-oxo-4H-chromene-3-carboxamide, C17H13NO4, (4a), N-(4-methyl-phen-yl)-4-oxo-4H-chromene-3-car...

The title compound, C(26)H(18)BrNO(4), features a functionalized chromene. The cyclo-hexene ring adopts a sofa conformation and has the nitro group and the bromo-phenyl ring in an axial position. The ten atoms of the chromene moiety lie close to a common plane (r.m.s. deviation = 0.066 Å). The attached phenyl ring is twisted by 32.89 (10)° from the chromene plane. The crystal packing is stabili...

Four N-(4-halophen-yl)-4-oxo-4H-chromene-3-carboxamides (halo = F, Cl, Br and I), N-(4-fluoro-phen-yl)-4-oxo-4H-chromene-3-carboxamide, C16H10FNO3, N-(4-chloro-phen-yl)-4-oxo-4H-chromene-3-carboxamide, C16H10ClNO3, N-(4-bromo-phen-yl)-4-oxo-4H-chromene-3-carboxamide, C16H10BrNO3, N-(4-iodo-phen-yl)-4-oxo-4H-chromene-3-carboxamide, C16H10INO3, have been structurally characterized. The mol-ecules...

The title compound, C(26)H(18)Cl(2)O, is a heterocyclic structure consisting of a benzo[f]chromene ring and two aromatic rings. The non-H atoms of the benzo[f]chromene ring are almost coplanar (rms deviation = 0.107 Å), and the methyl C atom lies 1.340 (4) Å from the mean plane of the benzo[f]chromene ring. The chromene ring forms dihedral angles of 88.45 (2)° with the benzene ring linked to th...

In the title compound, C18H19BrN2O4, the chromene unit is not quite planar (r.m.s. deviation = 0.199 Å), with the methyl C atoms lying 0.027 (4) and 1.929 (4) Å from the mean plane of the chromene unit. The six-membered carbocyclic ring of the chromene moiety adopts an envelope conformation, with the dimethyl-substituted C atom as the flap. The methyl-amine and nitro groups are slightly twisted...

From the methanol extract of the aerial parts of Peperomia blanda (Piperaceae), two chromenes were isolated and characterized mainly through application of 2D-NMR spectroscopy. The structures were 2S-(4-methyl-3-pentenyl)-6-formyl-8-hydroxy-2,7-dimethyl-2H-chromene and 2S-(4-methyl-3-pentenyl)-5-hydroxy-6-formyl-2,7-dimethyl-2H-chromene named as blandachromenes I and II, respectively.

Abstract 4-(2-Pyridylazo)resorcinol (PAR) sodium salt reacts with aromatic aldehydes and malononitrile in aqueous ethanol to form 2-amino-4-aryl-5-hydroxy-6-(2-pyridylazo)-4 H -chromene-3-carbonitriles.

A new chromene derivative, 2-(4',8'-dimethylnona-3'E,7'-dienyl)-8-hydroxy-2,6-dimethyl-2H-chromene (1) together with four known natural products, methylfarnesylquinone (2), isololiolide (3), pheophytin a (4), and β-carotene (5) were isolated from the brown alga Homoeostrichus formosana. The structure of 1 was determined by extensive 1D and 2D spectroscopic analyses. Acetylation of 1 yielded the...

In the title compound, C(16)H(9)BrO(5)·2C(3)H(7)NO, the chromene ring system is essentially planar. The two dimethyl-formamide solvent mol-ecules are linked by inter-molecular O-H⋯O hydrogen bonds to the 6-bromo-3-hydr-oxy-4-oxo-2-phenyl-4H-chromene-8-carboxylic acid molecules.

In the title compound, C(16)H(17)NO(4)S(2), the 2H-chromene ring system is nearly planar, with a maximum deviation of 0.070 (1) Å, and the morpholine ring adopts a chair conformation; the bond-angle sum for its N atom is 357.9°. The dihedral angle between the the 2H-chromene ring and the best plane through the morpholine ring is 89.09 (6)°. An intra-molecular C-H⋯S hydrogen bond occurs. In the ...