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1.  6-Amino-3-methyl-4-(3,4,5-tri­meth­oxy­phen­yl)-2,4-di­hydro­pyrano[2,3-c]pyrazole-5-carbo­nitrile 
In the title compound, C17H18N4O4, the dihedral angle between the benzene ring and 2,4-di­hydro­pyrano[2,3-c]pyrazole ring system is 89.41 (7)°. The pyran moiety adopts a strongly flattened boat conformation. In the crystal, mol­ecules are linked by N—H⋯N, N—H⋯O, C—H⋯N and C—H⋯O hydrogen bonds into an infinite two-dimensional network parallel to (110). There are π–π inter­actions between the pyrazole rings in neighbouring layers [centroid–centroid distance = 3.621 (1) Å].
PMCID: PMC4158517  PMID: 25249920
crystal structure
2.  Ethyl 6-amino-5-cyano-4-phenyl-2,4-di­hydro­pyrano[2,3-c]pyrazole-3-carboxyl­ate dimethyl sulfoxide monosolvate 
In the asymmetric unit of the title compound, C16H14N4O3·C2H6OS, there are two independent main mol­ecules (A and B) and two dimethyl sulfoxide solvent mol­ecules. In mol­ecule A, the pyran ring is in a flattened sofa conformation, with the sp 3-hydridized C atom forming the flap. In mol­ecule B, the pyran ring is in a flattened boat conformation, with the sp 3-hydridized C atom and the O atom deviating by 0.073 (3) and 0.055 (3) Å, respectively, from the plane of the other four atoms. The mean planes the pyrazole and phenyl rings form dihedral angles of 84.4 (2) and 84.9 (2)°, respectively, for mol­ecules A and B. In the crystal, N—H⋯O and N—H⋯N hydrogen bonds link the components of the structure into chains along [010]. In both solvent mol­ecules, the S atoms are disordered over two sites, with occupancy ratios of 0.679 (4):0.321 (4) and 0.546 (6):0.454 (6).
PMCID: PMC4120557  PMID: 25161577
3.  5-Hy­droxy-8,8-dimethyl-10-(2-methyl­but-3-en-2-yl)-2H,6H-7,8-dihydro­pyrano[3,2-g]chromene-2,6-dione 
In the title compound, C19H20O5, the pyran ring is in an envelope conformation, whereas the benzene and dihydro­pyran ring system is planar with an r.m.s. deviation of 0.0190 (1) Å. The hy­droxy group is coplanar with the attached benzene ring [r.m.s. deviation = 0.0106 (1) Å]. An intra­molecular O—H⋯O hydrogen bond generates an S(6) ring motif. In the crystal, mol­ecules are linked into chains along the b axis by weak C—H⋯O inter­actions. These chains are stacked along the a axis. C—H⋯π and weak π–π inter­actions [centroid–centroid distance = 3.7698 (7) Å] are also observed.
PMCID: PMC3051790  PMID: 21523091
4.  10-Methyl-2-oxo-4-phenyl-2,11-di­hydro­pyrano[2,3-a]carbazole-3-carbo­nitrile 
In the title mol­ecule, C23H14N2O2, the atoms in the carbazole unit deviate from planarity [maximum deviation from mean plane = 0.1018 (8) Å]. The pyrrole ring makes dihedral angles of 4.44 (5), 3.84 (5), 2.18 (5) and 56.44 (5)° with the pyran, fused benzene rings and phenyl ring, respectively. In the crystal, pairs of N—H⋯O hydrogen bonds generate R 2 2(14) loops and a C—H⋯N inter­action is also found. Mol­ecules are further linked by a number of π–π interactions [centroid–centroid distances vary from 3.5702 (5) to 3.7068 (6) Å], forming a three-dimensional network.
PMCID: PMC3684919  PMID: 23795021
5.  6-Amino-1-benzyl-4-(4-chloro­phen­yl)-3-(4-pyrid­yl)-1,4-dihydro­pyrano[2,3-c]pyrazole-5-carbonitrile 
The crystal structure of the title compound, C25H18ClN5O, was determined in the course of our studies on the synthesis of 1,4-dihydro­pyrano[2,3-c]pyrazole as an inhibitor of the p38 mitogen-activated protein kinase (MAPK). The compound was prepared via a base-catalysed synthesis from 1-benzyl-3-(4-pyrid­yl)-1H-pyrazol-5(4H)-one with p-chloro­aldehyde and malononitrile. The crystal data obtained were used to generate a three-dimensional pharmacophore model for in silico database screening. The phenyl ring is disordered over two positions, with site occupancy factors of 0.55 and 0.45. The dihedral angles between the 1,4-dihydropyrano[2,3-c]pyrazole unit and the chloro­phenyl and pyridine rings are 83.7 (1) and 16.0 (1)°, respectively. The chloro­phenyl and pyridine rings make a dihedral angle of 86.8 (2)°.
PMCID: PMC2960986  PMID: 21202092
6.  2,2,9-Trimethyl-2,3-dihydro­pyrano[2,3-a]carbazol-4-(11H)-one 
The title compound, C18H17NO2, was prepared from 1-hydr­oxy-7-methyl­carbazole and 3,3-dimethyl­acrylic acid with trifluoro­acetic acid as the cyclization catalyst. The mol­ecules contain an essentially planar 6-methyl­indole unit. The second aromatic ring is significantly bent away from the plane of this unit, with maximum deviations of 0.171 (1) and 0.185 (1) Å for two of the C atoms. In the crystal structure, there are neither N—H⋯O hydrogen bonds nor π–π stacking between the aromatic sections of neighboring mol­ecules. There is only one weak C—H⋯O hydrogen bond and a number of weak C—H⋯π inter­actions.
PMCID: PMC2959763  PMID: 21581016
7.  8-Meth­oxy-3,3,5-trimethyl-3,11-dihydro­pyrano[3,2-a]carbazole 
In the title compound, C19H19NO2, commonly called koenimbine, the pyran ring adopts a sofa conformation. The carbazole ring system is planar [r.m.s. deviation = 0.063 (1) Å]. A C(10) zigzag chain running along the b axis is formed through inter­molecular C—H⋯O hydrogen bonds. The chains are linked via weak C—H⋯π and N—H⋯π inter­actions.
PMCID: PMC3006796  PMID: 21587821
8.  3,4-Dimethyl-1-phenyl­pyrano[2,3-c]pyrazol-6(1H)-one 
In the title compound, C14H12N2O2, the dihedral angle between the phenyl ring and the 3,4-dimethyl­pyrano[2,3-c]pyrazol-6(1H)-one system is 7.28 (6)°. An intra­molecular C—H⋯O inter­action generates an S(6) ring. In the crystal, the mol­ecules are linked by C—H⋯O hydrogen bonds, forming C(8) chains. C–H⋯π and π–π inter­actions [centroid–centroid separation = 3.6374 (12) Å] further consolidate the packing.
PMCID: PMC3099778  PMID: 21754037
9.  6-Amino-3-methyl-4-(3-nitro­phen­yl)-1-phenyl-1H,4H-pyrano[2,3-c]pyrazole-5-carbonitrile 
The title compound, C20H15N5O3, was synthesized by the one-pot reaction of a four-component reaction protocol in aqueous medium. The pyrano[2,3-c]pyrazole system is essentially planar, with a maximum deviation of 0.026 (2) Å. The 3-nitro­phenyl and phenyl rings make dihedral angles of 81.11 (5) and 13.36 (1)°, respectively, with the mean plane of the pyrano[2,3-c]pyrazole ring. The crystal structure is stabilized by N—H⋯N hydrogen bonds, which form infinite chain propagating along the c axis and by N—H⋯O hydrogen bonds, which form infinite chains propagating along the a axis. There are also N—O⋯N—C dipole–dipole inter­actions along the a axis with an O⋯N distance of 3.061 (3) Å, which is shorter than that of the N—H⋯O hydrogen bond [3.196 (3) Å].
PMCID: PMC3120331  PMID: 21754828
10.  (6bS*,14R*,14aR*)-Methyl 14-(4-methyl­phen­yl)-7-oxo-6b,6c,7,12b,14,14a-hexa­hydro-1H-pyrano[3,2-c:5,4-c′]dichromene-14a-carboxyl­ate 
In the title compound, C28H22O6, the chromeno ring system is almost planar, with a dihedral angle between the mean planes of the pyran and benzene rings of 1.87 (8)°. The pyran ring bearing the methyl­phenyl substituent has a half-chair conformation while the other pyran ring has an envelope conformation with the tetra­substituted C atom as the flap. The benzene ring of the chromeno ring system is inclined to the benzene ring fused to the latter pyran ring by 74.66 (9)°. These aromatic rings are inclined to the 4-methyl­phenyl ring by 52.67 (9) and 66.63 (10)°, respectively. In the crystal, mol­ecules are linked via C—H⋯O hydrogen bonds, forming a two-dimensional network parallel to the bc plane.
PMCID: PMC3569797  PMID: 23424543
11.  8-Methyl-2-[4-(trifluoro­meth­yl)phen­yl]-8H-pyrazolo­[4,3-e][1,2,4]triazolo[1,5-c]pyrimidin-5-amine methanol disolvate 
In the title compound, C14H10F3N7·2CH4O, the heterocyclic ring system is essentially planar (r.m.s. deviation = 0.009 Å) and makes a dihedral angle of 6.91 (8)° with the attached benzene ring. In the crystal, the main mol­ecules form centrosymmetric R 2 2(8) dimers via pairs of N—H⋯N hydrogen bonds between the amino groups and pyrimidine N atoms. One of the independent methanol mol­ecules and its inversion equivalent are linked to the dimers via O—H⋯N and N—H⋯O hydrogen bonds, forming R 4 4(16) graph-set motifs. The dimers along with the hydrogen-bonded methanol mol­ecules are stacked along the a axis, with π–π inter­actions between the pyrazole and triazole rings [centroid–centroid distance = 3.4953 (10) Å].
PMCID: PMC3007048  PMID: 21588038
12.  4-Methyl-9-[(4-methyl­phen­yl)sulfon­yl]thio­pyrano[3,4-b]indole-3(9H)-thione 
The title compound, C19H15NO2S3, is the first example of a dithia analogue of pyrano[3,4-b]indolone. The almost planar thio­pyrano­indole­thione ring system (r.m.s. deviation for all non-H atoms = 0.030 Å) makes a dihedral angle of 80.70 (8)° with the p-tolyl ring. In the crystal, mol­ecules are connected via C—H⋯O hydrogen bonds into two chains along the b axis. These chains are connected via π–π inter­actions between symmetry-related thio­pyrano­indole­thione ring systems [centroid–centroid distance = 3.588 (1) Å].
PMCID: PMC2983115  PMID: 21587636
13.  2-Amino-7,7-dimethyl-5-oxo-4-[3-(trifluoro­meth­yl)phen­yl]-1,4,5,6,7,8-hexa­hydro­quinoline-3-carbonitrile 
In the title mol­ecule, C19H18F3N3O, the dihydro­pyridine and cyclo­hexene rings both adopt sofa conformations. The five essentially planar atoms of the dihydro­pyridine ring [maximum deviation = 0.039 (2) Å] form a dihedral angle of 88.19 (8)° with the benzene ring. The F atoms of the trifluoro­methyl group were refined as disordered over two sets of sites in a 0.840 (3):0.160 (3) ratio. In the crystal, N—H⋯O and N—H⋯N hydrogen bonds link mol­ecules into a two-dimensional network parallel to (100).
PMCID: PMC3588344  PMID: 23476367
14.  rac-Diethyl 5-oxo-2-[(2,4,4-trimethyl­pentan-2-yl)amino]-4,5-dihydro­pyrano[3,2-c]chromene-3,4-dicarboxyl­ate 
The title compound, C26H33NO7, comprises a racemic mixture of asymmetric mol­ecules containing one stereogenic centre. The dihedral angle between the mean planes of the fused pyran ring and the coumarin ring system is 8.12 (14)°. The mol­ecular structure features a short N—H⋯O contact, which generates an S(6) ring motif. The crystal packing are stabilized by C—H⋯O inter­actions.
PMCID: PMC3254459  PMID: 22259399
15.  2,2,10-Trimethyl-2,3-dihydro­pyrano[2,3-a]carbazol-4(11H)-one 
The title compound, C18H17NO2, was prepared from 1-hydr­oxy-8-methyl­carbazole and 3,3-dimethyl­acrylic acid with trifluoro­acetic acid as the cyclization catalyst. Due to the –CMe2– group, the mol­ecule is not quite planar. The packing is dominated by the strong N—H⋯O hydrogen bonds and some weaker C—H⋯O and C—H⋯π inter­actions. π–π Stacking inter­actions [centroid–centroid separation = 3.806 (2) Å] join neighboring mol­ecules into loosely connected inversion dimers.
PMCID: PMC2959518  PMID: 21581017
16.  2,2-Dimethyl-2,3-dihydro­pyrano[2,3-a]carbazol-4(11H)-one 
The title compound, C17H15NO2, was prepared from 1-hydroxy­carbazole and 3,3-dimethyl­acrylic acid with a mixture of AlCl3 and POCl3 as the cyclization catalyst. Owing to the presence of the –CMe2– group, the mol­ecule is not quite planar. In the crystal structre, strong N—H⋯O hydrogen bonds and weaker C—H⋯π inter­actions occur, and a slipped π–π stacking inter­action [centroid–centroid separation = 3.8425 (8) Å] is also observed.
PMCID: PMC2959512  PMID: 21581015
17.  1-Phenyl-2-[4-(trifluoro­meth­yl)phen­yl]-1H-benzimidazole 
In the title mol­ecule, C20H13F3N2, the benzimidazole unit is close to being planar [maximum deviation = 0.012 (1) Å] and forms dihedral angles of 31.43 (7) and 61.45 (9)° with the 4-(trifluoromethyl)phenyl and 1-phenyl rings, respectively; the dihedral angle between these rings is 60.94 (10)°. In the crystal, C—H⋯F hydrogen bonds link the mol­ecules into chains along the c-axis direction. The CF3 group is rotationally disordered with an occupancy ratio of 0.557 (8):0.443 (8) for the F atoms.
PMCID: PMC3569777  PMID: 23424523
18.  3-Meth­oxy-2-[2-({[6-(trifluoro­meth­yl)pyridin-2-yl]­oxy}meth­yl)phen­yl]prop-2-enoic acid 
The title mol­ecule, C17H14F3NO4, consists of two nearly planar fragments, viz. the 2-benzyl­oxypyridine (r.m.s. deviation 0.016 Å) and (E)-3-meth­oxy­prop2-enoic (r.m.s. deviation 0.004 Å) units, which form a dihedral angle of 84.19 (7)°. In the crystal, pairs of O—H⋯O hydrogen bonds link mol­ecules into dimers that are further connected by C—H⋯O and C—H⋯F inter­actions into (001) layers. In addition, π–π stacking inter­actions are observed within a layer between the pyridine and benzene rings [centroid–centroid distance = 3.768 (2) Å]. The F atoms of the trifluoro­methyl group are disordered over two sets of sites in a 0.53 (4):0.47 (4) ratio.
PMCID: PMC3515258  PMID: 23284478
19.  cis-3-Methyl-1-phenyl-8a,9,10,11,12,12a,12b-hexa­hydro-1H,3bH-pyrazolo[3,4:2′,3′]pyrano[4′,5′,6′-kl]xanthene 
The asymmetric unit of the title compound, C23H22N2O2, contains two independent mol­ecules, A and B. The cyclo­hexane ring of mol­ecule B is disordered, with occupancies for the major and minor conformers of 0.570 (9) and 0.430 (9), respectively. The cyclo­hexane ring adopts a boat conformation in mol­ecule A and in the major conformer of mol­ecule B, and a chair conformation in the minor conformer of mol­ecule B. In both independent mol­ecules, one of the dihydro­pyran rings adopts a boat conformation while the other is in a half-chair conformation. The dihedral angle between the pyrazole and phenyl rings is 16.0 (1)° in mol­ecule A and 12.9 (1)° in mol­ecule B. The crystal packing is stabilized by C—H⋯O and C—H⋯N inter­molecular hydrogen bonds.
PMCID: PMC2915303  PMID: 21200811
20.  5-Chloro-3,6-dimethyl-1-phenyl-1H,4H-pyrano[2,3-c]pyrazol-4-one 
In the title compound, C14H11ClN2O2, two independent mol­ecules (A and B) comprise the asymmetric unit with the main difference between them being the relative orientation of the pendent phenyl ring with respect to the fused-ring system [dihedral angles = 8.32 (8)° (A) and 28.32 (8)° (B)]. In the crystal, the A mol­ecules are connected into a linear supra­molecular chain along the a axis via C—H⋯O inter­actions and linked to this via C—H⋯Cl inter­actions are the B mol­ecules. The chains are connected into layers in the ab plane by π–π inter­actions between pyrazole (A) and pyran (B) rings, and between pyrazole (B) and pyran (A) rings [centroid–centroid distances = 3.5442 (11) and 3.4022 (10) Å, respectively].
PMCID: PMC3394042  PMID: 22798907
21.  1-[2-Oxo-5-(trifluoro­meth­oxy)indolin-3-yl­idene]-4-[4-(trifluoro­methyl)­phen­yl]thio­semicarbazide 
In the title compound, C17H10F6N4O2S, an intra­molecular N—H⋯N hydrogen bonds forms an S(5) ring whereas N—H⋯O and C—H⋯S inter­actions complete S(6) ring motifs. The dihedral angle between the fused ring system and the phenyl ring is 6.68 (8)°. In the crystal, the mol­ecules are dimerized due to N—H⋯O inter­actions. π–π inter­actions are present between the benzene rings [centroid–centroid distance = 3.6913 (15) Å] and between the five membered ring and the trifluoro­meth­yl)phenyl ring [centroids–centroid distance = 3.7827 (16) Å]. One of the trifluoro­meth­oxy F atoms is disordered over two sites with occupancy ratio of 0.76 (3):0.24 (3). The F atoms of the p-trifluoro­methyl substituent are disordered over three sets of sites with an occupancy ratio of 0.70 (2):0.152 (11):0.147 (13).
PMCID: PMC3006819  PMID: 21587965
22.  1-[4-Chloro-3-(trifluoro­meth­yl)phen­yl]-4-phenyl-1H-1,2,3-triazole 
In the title compound, C15H9ClF3N3, the phenyl and chloro-trifluoro­methyl benzene rings are twisted with respect to the planar triazole group, making dihedral angles of 21.29 (12) and 32.19 (11)°, respectively. In the crystal, the mol­ecules pack in a head-to-tail arrangement along the a axis with closest inter-centroid distances between the triazole rings of 3.7372 (12) Å.
PMCID: PMC3515254  PMID: 23284474
23.  8-[(3,3-Dimethyl­oxiran-2-yl)methoxy­meth­yl]-11-hydr­oxy-2-isopropenyl-5-methyl-12-oxo-1,2,3,12-tetra­hydro­pyrano[3,2-a]xanthen-1-yl acetate 
The title compound, commonly known as 14-methoxy­tajixanthone-25-acetate, C28H30O8, was isolated from Emericella variecolor. The central xanthone core is approximately planar (r.m.s. deviation = 0.084 Å). The dihydro­pyran ring adopts a distorted half-chair conformation. The oxirane plane is oriented at an angle of 63.3 (2)° with respect to the phenol group. An intra­molecular O—H⋯O hydrogen bond forms an S(6) ring. In the crystal, mol­ecules are linked into a two-dimensional network parallel to the ab plane by weak inter­molecular C—H⋯O hydrogen bonds.
PMCID: PMC2970346  PMID: 21577999
24.  2-Chloro-N-{3-cyano-1-[2,6-dichloro-4-(trifluoro­meth­yl)phen­yl]-1H-pyrazol-5-yl}acetamide 
The title compound, C13H6Cl3F3N4O, was synthesized by the reaction of 5-amino-1-[2,6-dichloro-4-(trifluoro­meth­yl)phen­yl]-1H-pyrazole-3-carbonitrile and 2-chloro­acetyl chloride. The five-membered pyrazole ring makes a dihedral angle of 71.5 (3)° with the benzene ring. The –CF3 group is disordered by rotation, and the F atoms are split over two sets of sites with occupancies of 0.59 (2) and 0.41 (2). The crystal structure features weak C—H⋯O and N—H⋯N inter­actions involving the carbonyl and cyano groups as acceptors.
PMCID: PMC3254452  PMID: 22259391
25.  (E)-7-(4-Chloro­phen­yl)-5,7-dihydro-4H-pyrano[3,4-c]isoxazole-3-carbaldehyde oxime 
In the title compound, C13H11ClN2O3, the nine-membered bicycle includes an oxime group having the C=N group in an E configuration. The isoxazole ring is almost planar [r.m.s. deviation = 0.0056 Å]; the dihedral angle between the isoxazole and 4-chloro­phenyl ring is 75.60 (5)°. In the crystal, inter­molecular O—H⋯Nisoxazole hydrogen bonds give rise to chains running along the b axis.
PMCID: PMC3052067  PMID: 21522420

Results 1-25 (90560)