The crystal structures of fourN-(4-halophenyl)-4-oxo-4H-chromene-3-carboxamides

Four N-(4-halophen­yl)-4-oxo-4H-chromene-3-carboxamides (halo = F, Cl, Br and I), N-(4-fluoro­phen­yl)-4-oxo-4H-chromene-3-carboxamide, C16H10FNO3, N-(4-chloro­phen­yl)-4-oxo-4H-chromene-3-carboxamide, C16H10ClNO3, N-(4-bromo­phen­yl)-4-oxo-4H-chromene-3-carboxamide, C16H10BrNO3, N-(4-iodo­phen­yl)-4-oxo-4H-chromene-3-carboxamide, C16H10INO3, have been structurally characterized. The mol­ecules are essentially planar and each exhibits an anti conformation with respect to the C—N rotamer of the amide and a cis geometry with respect to the relative positions of the Carom—Carom bond of the chromone ring and the carbonyl group of the amide. The structures each exhibit an intra­molecular hydrogen-bonding network comprising an N—H⋯O hydrogen bond between the amide N atom and the O atom of the carbonyl group of the pyrone ring, forming an S(6) ring, and a weak Carom—H⋯O inter­action with the O atom of the carbonyl group of the amide as acceptor, which forms another S(6) ring. All four compounds have the same supra­molecular structure, consisting of R 2 2(13) rings that are propagated along the a-axis direction by unit translation. There is π–π stacking involving inversion-related mol­ecules in each structure.info:eu-repo/semantics/publishedVersio

Crystal structures of two 6-(2-hydroxybenzoyl)-5H-thiazolo[3,2-a]pyrimidin-5-ones

he title compounds, 6-(2-hy­droxy­benz­yl)-5H-thia­zolo[3,2-a]pyrimidin-5-one, C13H8N2O3S, (1), and 6-(2-hy­droxy­benz­yl)-3-methyl-5H-thia­zolo[3,2-a]pyrimidin-5-one, C14H10N2O3S, (2), were synthesized when a chromone-3-carb­oxy­lic acid, activated with (benzotriazol-1-yl­oxy)tripyrrolidinyl­phospho­nium hexa­fluorido­phosphate (PyBOP), was reacted with a primary heteromamine. Instead of the expected amidation, the unusual title thia­zolo­pyrimidine-5-one derivatives were obtained serendipitously and a mechanism of formation is proposed. Both compounds present an intra­molecular O-H...O hydrogen bond, which generates an S(6) ring. The dihedral angles between the heterocyclic moiety and the 2-hydroxybenzoyl ring are 55.22 (5) and 46.83 (6)° for (1) and (2), respectively. In the crystals, the mol­ecules are linked by weak C-H...O hydrogen bonds and [pi]-[pi] stacking inter­actions.info:eu-repo/semantics/publishedVersio

A comparison of the structures of some 2- and 3-substituted chromone derivatives: a structural study on the importance of the secondary carboxamide backbone for the inhibitory activity of MAO-B

The crystal structures of the 3-substituted tertiary chromone carboxamide derivative, C17H13NO3, N-methyl-4-oxo-N-phenyl-4H-chromene-3-carboxamide (1), and the chromone carbonyl pyrrolidine derivatives, C14H13NO3, 3-(pyrrolidine-1-carbon­yl)-4H-chromen-4-one (3) and 2-(pyrrolidine-1-carbon­yl)-4H-chromen-4-one (4) have been determined. Their structural features are discussed and compared with similar compounds namely with respect to their MAO-B inhibitory activities. The chromone carboxamide presents a -syn conformation with the aromatic rings twisted with respect to each other [the dihedral angle between the mean planes of the chromone system and the exocyclic phenyl ring is 58.48 (8)°]. The pyrrolidine derivatives also display a significant twist: the dihedral angles between the chromone system and the best plane formed by the pyrrolidine atoms are 48.9 (2) and 23.97 (12)° in (3) and (4), respectively. Compound (3) shows a short C-H...O intra­molecular contact forming an S(7) ring. The supra­molecular structures for each compound are defined by weak C-H...O hydrogen bonds, which link the mol­ecules into chains and sheets. The Cambridge Structural Database gave 45 hits for compounds with a pyrrolidinecarbonyl group. A simple statistical analysis of their geometric parameters is made in order to compare them with those of the mol­ecules determined in the present work.info:eu-repo/semantics/publishedVersio

New insights in the discovery of novelh-MAO-B inhibitors: structural characterization of a series ofN-phenyl-4-oxo-4H-chromene-3-carboxamide derivatives

Six N-substituted-phenyl 4-oxo-4H-chromene-3-carboxamides, namely N-(2-nitro­phen­yl)-4-oxo-4H-chromene-3-carboxamide, C16H10N2O5 (2b), N-(3-meth­oxy­phen­yl)-4-oxo-4H-chromene-3-carboxamide, C17H13NO4, (3a), N-(3-bromo­phen­yl)-4-oxo-4H-chromene-3-carboxamide, C16H10BrNO3, (3b), N-(4-methoxy­phen­yl)-4-oxo-4H-chromene-3-carboxamide, C17H13NO4, (4a), N-(4-methyl­phen­yl)-4-oxo-4H-chromene-3-carboxamide, C17H13NO3, (4d), and N-(4-hy­droxy­phen­yl)-4-oxo-4H-chromene-3-carboxamide, C16H11NO4, (4e), have been structurally characterized. All compounds exhibit an anti conformation with respect to the C—N rotamer of the amide and a trans-related conformation with the carbonyl groups of the chromone ring of the amide. These structures present an intra­molecular hydrogen-bonded network comprising an N—H⋯O hydrogen bond between the amide N atom and the O atom of the carbonyl group of the pyrone ring, forming an S(6) ring, and a weak Car—H⋯O hydrogen bond in which the carbonyl group of the amide acts as acceptor for the H atom of an ortho-C atom of the exocyclic phenyl ring, which results in another S(6) ring. The N—H⋯O intra­molecular hydrogen bond constrains the carboxamide moiety such that it is virtually coplanar with the chromone ring.info:eu-repo/semantics/publishedVersio

Crystal structures of three 3,4,5-trimethoxybenzamide-based derivatives

The crystal structures of three benzamide derivatives, viz. N-(6-hy-droxy-hex-yl)-3,4,5-tri-meth-oxy-benzamide, C16H25NO5, (1), N-(6-anilinohex-yl)-3,4,5-tri-meth-oxy-benzamide, C22H30N2O4, (2), and N-(6,6-di-eth-oxy-hex-yl)-3,4,5-tri-meth-oxy-benzamide, C20H33NO6, (3), are described. These compounds differ only in the substituent at the end of the hexyl chain and the nature of these substituents determines the differences in hydrogen bonding between the mol-ecules. In each mol-ecule, the m-meth-oxy substituents are virtually coplanar with the benzyl ring, while the p-meth-oxy substituent is almost perpendicular. The carbonyl O atom of the amide rotamer is trans related with the amidic H atom. In each structure, the benzamide N-H donor group and O acceptor atoms link the mol-ecules into C(4) chains. In 1, a terminal -OH group links the mol-ecules into a C(3) chain and the combined effect of the C(4) and C(3) chains is a ribbon made up of screw related R 2 (2)(17) rings in which the ⋯O-H⋯ chain lies in the centre of the ribbon and the tri-meth-oxy-benzyl groups forms the edges. In 2, the combination of the benzamide C(4) chain and the hydrogen bond formed by the terminal N-H group to an O atom of the 4-meth-oxy group link the mol-ecules into a chain of R 2 (2)(17) rings. In 3, the mol-ecules are linked only by C(4) chains.info:eu-repo/semantics/publishedVersio

Crystal structures of ethyl 6-(4-methylphenyl)-4-oxo-4H-chromene-2-carboxylate and ethyl 6-(4-fluorophenyl)-4-oxo-4H-chromene-2-carboxylate

The crystal structures of two chromone derivatives, viz. ethyl 6-(4-methyl­phen­yl)-4-oxo-4H-chromene-2-carboxyl­ate, C19H16O4, (1), and ethyl 6-(4-fluoro­phen­yl)-4-oxo-4H-chromene-2-carboxyl­ate C18H13FO4, (2), have been determined: (1) crystallizes with two mol­ecules in the asymmetric unit. A comparison of the dihedral angles beween the mean planes of the central chromone core with those of the substituents, an ethyl ester moiety at the 2-position and a para-substituted phenyl ring at the 6-position shows that each mol­ecule differs significantly from the others, even the two independent mol­ecules (a and b) of (1). In all three mol­ecules, the carbonyl groups of the chromone and the carboxyl­ate are trans-related. The supra­molecular structure of (1) involves only weak C-H...[pi] inter­actions between H atoms of the substituent phenyl group and the phenyl group, which link mol­ecules into a chain of alternating mol­ecules a and b, and weak [pi]-[pi] stacking inter­actions between the chromone units. The packing in (2) involves C-H...O inter­actions, which form a network of two inter­secting ladders involving the carbonyl atom of the carboxyl­ate group as the acceptor for H atoms at the 7-position of the chromone ring and from an ortho-H atom of the exocyclic benzene ring. The carbonyl atom of the chromone acts as an acceptor from a meta-H atom of the exocyclic benzene ring. [pi]-[pi] inter­actions stack the mol­ecules by unit translation along the a axis.info:eu-repo/semantics/publishedVersio

Crystal structures of five 6-mercaptopurine derivatives

The crystal structures of five 6-mercaptopurine derivatives, viz. 2-[(9-acetyl-9H-purin-6-yl)sulfan-yl]-1-(3-meth-oxy-phen-yl)ethan-1-one (1), C16H14N4O3S, 2-[(9-acetyl-9H-purin-6-yl)sulfan-yl]-1-(4-meth-oxy-phen-yl)ethan-1-one (2), C16H14N4O3S, 2-[(9-acetyl-9H-purin-6-yl)sulfan-yl]-1-(4-chloro-phen-yl)ethan-1-one (3), C15H11ClN4O2S, 2-[(9-acetyl-9H-purin-6-yl)sulfan-yl]-1-(4-bromo-phen-yl)ethan-1-one (4), C15H11BrN4O2S, and 1-(3-meth-oxy-phen-yl)-2-[(9H-purin-6-yl)sulfan-yl]ethan-1-one (5), C14H12N4O2S. Compounds (2), (3) and (4) are isomorphous and accordingly their mol-ecular and supra-molecular structures are similar. An analysis of the dihedral angles between the purine and exocyclic phenyl rings show that the mol-ecules of (1) and (5) are essentially planar but that in the case of the three isomorphous compounds (2), (3) and (4), these rings are twisted by a dihedral angle of approximately 38°. With the exception of (1) all mol-ecules are linked by weak C-H⋯O hydrogen bonds in their crystals. There is π-π stacking in all compounds. A Cambridge Structural Database search revealed the existence of 11 deposited compounds containing the 1-phenyl-2-sulfanyl-ethanone scaffold; of these, only eight have a cyclic ring as substituent, the majority of these being heterocycles.info:eu-repo/semantics/publishedVersio

Crystal structures, Hirshfeld surface analysis and a computational study of four ethyl 2-oxo-2H-chromene-3-carboxylate derivatives : a survey of organyl 2-oxo-2H-chromene-3-carboxylate structures

LRG thanks the Portuguese Foundation for Science and Technology (FCT) UID/Multi/04546/2013.for support. TvM is grateful to EaStCHEM for computational support via the EaStCHEM Research Computing Facility. JLW thanks CNPq, Brazil for support.Crystal structures, Hirshfeld surface analysis and a computational study have been carried out on 2-oxo-2H-chromene-3-carboxylates. Crystal structures are reported for ethyl R-2-oxo-2H-chromene-3-carboxylate derivatives, 2a: R=6-Me, 2b: 7-Me, 2c: 7-Me, 2d: R=7-MeO. In contrast to 2-oxo-2H-chromene-3-carboxamides, 1, in which classical intramolecular N–H···O hydrogen bonds stabilize planar structures and hinder rotation of the amido group out of the coumarin plane in 2, without an equivalent hydrogen bond, there is a greater rotational freedom of the carboxylate group. The interplanar angles between the coumarin core and its attached –C(O)–R substituent in crystalline 2a, 2b, 2c and 2d are 10.41(6), 36.65(6), 10.4(2) and 5.64(6)°, respectively, with distances between the carbonyl oxygen atoms of 2.8255(16), 2.9278(16), 4.226(2) and 2.8328(14) Å, respectively. A theoretical study of molecular conformations was carried out at the M06-2X density level with the 6-31+G(d) and aug-cc-pVTZ basis sets, in methanol solution modeled by PCM, indicated that the most stable conformations had the carbonyl group of the ester in the plane of the coumarin core: the s-cis arrangement of the ester carbonyl and the 2-oxo moieties being the slightly more stable than the s-trans form by less than 0.5 kcal/mol. The experimental conformations of 2a and 2d match well the low energy s-cis arrangement, and 2c matches the slightly lesser stable s-trans arrangement found in the theoretical study. A survey of the molecular conformations of more than 50 2H-chromene-3-carboxylates derivatives in the CCDC data base indicated two distinct groupings of conformations, s-cis and s-trans, each with interplanar angles <30°.Publisher PDFPeer reviewe

4-(1-Naphth­yl)benzoic acid

In the title mol­ecule, C17H12O2, the dihedral angle between the mean plane of the benzene ring and that of the naphthalene ring system is 49.09 (6)°. In the crystal structure, mol­ecules are linked to form centrosymmetric dimers via inter­molecular O—H⋯O hydrogen bonds. The hydr­oxy H atom is disordered over two sites with refined occupancies of 0.62 (3) and 0.38 (3)

2,4,5-Tris(biphenyl-2-yl)-1-bromo­benzene

In the title compound, C42H29Br, the dihedral angles between the central benzene ring and the three attached benzene rings are very similar, lying in the range 52.65 (6)–57.20 (7)°. Of the dihedral angles between the rings of the o-biphenyl substituents, two are similar [46.34 (7) and 47.35 (7)°], while the other differs significantly [64.17 (7)°]. In the crystal, mol­ecules are linked into centrosymmetric dimers by two weak C—H⋯π inter­actions