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1.  Methyl 5-(4-hy­droxy-3-meth­oxy­phen­yl)-2-(4-meth­oxy­benzyl­idene)-7-methyl-3-oxo-2,3-dihydro-5H-thia­zolo[3,2-a]pyrimidine-6-carboxyl­ate 
In the title compound, C24H22N2O6S, a pyrimidine ring substituted with 4-hy­droxy-3-meth­oxy­phenyl is fused with a thia­zole ring. The 4-hy­droxy-3-meth­oxy­phenyl group is positioned axially to the pyrimidine ring, making a dihedral angle 85.36 (7)°. The pyrimidine ring adopts a twist boat conformation. In the crystal, O—H⋯N inter­actions result in a chain running along the b axis. The carbonyl O atom bonded to the thia­zole ring is involved in two C—H⋯O hydrogen-bond inter­actions forming centrosymmetric dimers; the ten- and six-membered rings resulting from these inter­actions have R 2 2(10) and R 1 2(6) motifs, respectively.
doi:10.1107/S1600536811048987
PMCID: PMC3239076  PMID: 22199924
2.  Ethyl (2Z)-2-(3-methoxy­benzyl­idene)-7-methyl-3-oxo-5-phenyl-2,3-dihydro-5H-1,3-thia­zolo[3,2-a]pyrimidine-6-carboxyl­ate 
In the title compound, C24H22N2O4S, the central pyrimidine ring is significantly puckered, assuming a conformation inter­mediate between a boat and a screw boat. The nearly planar thia­zole ring (r.m.s. deviation = 0.0258 Å) is fused with the pyriamidine ring, making a dihedral angle of 9.83 (7)°. The carboxyl group is in an extended conformation with an anti-periplanar orientation with respect to the dihydropyrimidine ring. The benzene ring linked at the chiral C atom is perpendicular to the pyrimidine ring [dihedral angle = 85.21 (8)°] whereas the phenyl ring is nearly coplanar, making a dihedral angle of 13.20 (8)°. An intra­molecular C—H⋯S hydrogen bond is observed. The crystal packing is influenced by weak inter­molecular C—H⋯π inter­actions and π–π stacking between the thia­zole and phenyl rings [centroid–centroid distance = 3.9656 (10) Å], which stack the mol­ecules along the c axis.
doi:10.1107/S1600536810004812
PMCID: PMC2983585  PMID: 21580360
3.  Crystal structure of ethyl 2-cyano-3-[(1-eth­oxy­ethyl­idene)amino]-5-(3-meth­oxy­phen­yl)-7-methyl-5H-1,3-thia­zolo[3,2-a]pyrimidine-6-carboxyl­ate 
In the title compound, C22H24N4O4S, the central pyrimidine ring adopts a sofa conformation with the ring-junction N atom displaced by 0.2358 (6) Å from the mean plane of the remaining ring atoms. The 3-meth­oxy­phenyl ring, at the chiral C atom opposite the other N atom, is positioned axially and is inclined to the thia­zolo­pyrimidine ring with a dihedral angle of 83.88 (7)°. The thia­zole ring is essentially planar (r.m.s. deviation = 0.0034 Å). In the crystal, pairs of weak C—H⋯O hydrogen bonds link mol­ecules related by twofold rotation axes to form R 2 2(8) rings, which in turn are linked by weak C—H⋯N inter­actions, forming ribbons along [-110]. In addition, π–π stacking inter­actions [centroid—centroid distance = 3.5744 (15) Å] connect the ribbons, forming slabs lying parallel to (001).
doi:10.1107/S2056989015005241
PMCID: PMC4438835  PMID: 26029443
crystal structure; pyrimidine; thia­zolo­pyrimidine; thia­zolo[3,2-a]pyrimidine; hydrogen bonding; π–π stacking inter­actions
4.  Crystal structure of 2-acetyl-5-(3,4-di­meth­oxy­phen­yl)-6-eth­oxy­carbonyl-3,7-dimethyl-5H-thia­zolo[3,2-a]pyrimidin-8-ium chloride 
The title mol­ecular salt, C21H25N2O5S+·Cl−, crystallizes with two ion pairs in the asymmetric unit. The cations have similar conformations (r.m.s. overlay fit = 0.40 Å), with one of them showing disorder of the terminal methyl group of the ester in a 0.72 (2):0.28 (2) ratio. In the first cation, the 3,4-dimeth­oxy-substituted phenyl ring subtends a dihedral angle of 88.38 (7)° with the pyrimidine ring and 6.79 (8)° with the thia­zole ring. The equivalent data for the second cation are 89.97 (3) and 6.42 (7)°, respectively. The pyrimidine ring adopts a sofa conformation in each cation. In the crystal, the components are linked by N—H⋯Cl hydrogen bonds, generating isolated ion pairs. The ion pairs are are linked by C—H⋯O inter­actions, generating a three-dimensional network. In addition, a weak C—H⋯π inter­action is observed.
doi:10.1107/S2056989015016229
PMCID: PMC4647379  PMID: 26594466
crystal structure; salt; pyrimidinium; chloride; pyrimidine derivatives; pharmacological properties; biological activity; hydrogen bonding; C—H⋯π inter­actions
5.  Crystal structure of ethyl 2-(2-fluoro­benzyl­idene)-5-(4-fluoro­phen­yl)-7-methyl-3-oxo-2,3-di­hydro-5H-1,3-thia­zolo[3,2-a]pyrimidine-6-carb­oxy­late 
In the title mol­ecule, C23H18F2N2O3S, the 4-fluoro-substituted and 2-fluoro-substituted benzene rings form dihedral angles of 88.16 (8) and 23.1 (1)°, respectively, with the thia­zole ring. The pyrimidine ring adopts a flattened sofa conformation with the sp 3-hydridized C atom forming the flap. In the crystal, pairs of weak C—H⋯O hydrogen bonds link mol­ecules related by twofold rotation axes, forming R 2 2(10) rings, which are in turn linked by weak C—H⋯N inter­actions to form chains of rings along [010]. In addition, weak C—H⋯π(arene) inter­actions link the chains into layers parallel to (001) and π–π inter­actions with a centroid–centroid distance of 3.836 (10) Å connect these layers into a three-dimensional network.
doi:10.1107/S1600536814025008
PMCID: PMC4257371  PMID: 25553039
crystal structure; fused pyrimidine derivative; fluoro-substituted compound; hydrogen bonding; C—H⋯π inter­actions; π–π inter­actions
6.  Methyl 5-(4-acet­oxy­phen­yl)-2-(2-bromo­benzyl­idine)-7-methyl-3-oxo-2,3-di­hydro-5H-1,3-thia­zolo[3,2-a]pyrimidine-6-carboxyl­ate 
In the title mol­ecule, C24H19BrN2O5S, the pyrimidine ring is in a flattened half-chair conformation and the 4-acet­oxy­phenyl group is substituted axially to this ring. The thia­zole ring is essentially planar [with a maximum deviation of 0.012 (2) Å for the N atom] and forms dihedral angles of 17.65 (13) and 88.95 (11)° with the bromo- and acet­oxy-substituted benzene rings, respectively. The dihedral angle between the benzene rings is 81.84 (13) Å. In the crystal, pairs of weak C—H⋯O hydrogen bonds lead to the formation of inversion dimers. A weak C—H⋯π inter­action and π–π stacking inter­actions with centroid–centroid distances of 3.5903 (14) Å are observed.
doi:10.1107/S1600536813019132
PMCID: PMC3793759  PMID: 24109346
7.  N-(4-Meth­oxy­phen­yl)-6-methyl-2-phenyl-5-{[4-(tri­fluoro­meth­yl)anilino]meth­yl}pyrimidin-4-amine 
The title compound, C26H23F3N4O, crystallizes with two symmetry-independent mol­ecules in the asymmetric unit, denoted A and B, which differ mainly in the rotation of the meth­oxy­phenyl ring. The –CF3 group of mol­ecule B is disordered by rotation, with the F atoms split over two sets of sites; the occupancy factor for the major component is 0.853 (4). The dihedral angles between the pyrimidine ring and the attached phenyl, meth­oxy­phenyl and tri­fluoro­methyl­phenyl rings are 8.1 (2), 37.5 (2) and 70.7 (2)°, respectively, in mol­ecule A, and 9.3 (2), 5.3 (2) and 79.7 (2)° in mol­ecule B. An intra­molecular N—H⋯N hydrogen bond occurs in each mol­ecule. In the crystal, two crystallographically independent mol­ecules associate into a dimer via a pair of N—H⋯N hydrogen bonds, with a resulting R 2 2(12) ring motif and π–π stacking inter­actions [centroid–centroid distance = 3.517 (4) Å] between the pyrimidine rings. For the A mol­ecules, there are inter­molecular C—H⋯O hydrogen bonds between an aryl C atom of meth­oxy­phenyl ring and a meth­oxy O atom of an adjacent mol­ecule. A similar inter­action is lacking in the B mol­ecules.
doi:10.1107/S160053681303170X
PMCID: PMC3885078  PMID: 24454254
8.  Crystal structure of (E)-4-hy­droxy-N′-(3-meth­oxy­benzyl­idene)benzohydrazide1  
The mol­ecules of C15H14N2O3 are slightly twisted. N—H⋯O, O—H⋯N and O—H⋯O hydrogen bonds play an important role in the crystal packing, resulting in the formation of mol­ecular sheets parallel to the bc plane.
The title compound, C15H14N2O3, crystallizes with two independent mol­ecules (A and B) in the asymmetric unit that differ in the orientation of the 3-meth­oxy­phenyl group with respect to the methyl­idenebenzohydrazide unit. The dihedral angles between the two benzene rings are 24.02 (10) and 29.30 (9)° in mol­ecules A and B, respectively. In mol­ecule A, the meth­oxy group is twisted slightly relative to its bound benzene ring, with a Cmeth­yl—O—C—C torsion angle of 14.2 (3)°, whereas it is almost co-planar in mol­ecule B, where the corresponding angle is −2.4 (3)°. In the crystal, the mol­ecules are linked by N—H⋯O, O—H⋯N and O—H⋯O hydrogen bonds, as well as by weak C—H⋯O inter­actions, forming sheets parallel to the bc plane. The N—H⋯O hydrogen bond and weak C—H⋯O inter­action link different mol­ecules (A⋯B) whereas both O—H⋯N and O—H⋯O hydrogen bonds link like mol­ecules (A⋯A) and (B⋯B). Pairs of inversion-related B mol­ecules are stacked approximately along the a axis by π–π inter­actions in which the distance between the centroids of the 3-meth­oxy­phenyl rings is 3.5388 (12) Å. The B mol­ecules also participate in weak C—H⋯π inter­actions between the 4-hy­droxy­phenyl and the 3-meth­oxy­phenyl rings.
doi:10.1107/S2056989016013268
PMCID: PMC5120720  PMID: 27920930
Benzohydrazides; α-glucosidase inhibitory; X-ray; crystal structure
9.  Ethyl 7-methyl-3-oxo-5-phenyl-2-(2,4,6-trimeth­oxy­benzyl­idene)-2,3-dihydro-5H-thia­zolo[3,2-a]pyrimidine-6-carboxyl­ate 
In the title compound, C26H26N2O6S, the benzene ring is positioned axially to the thia­zolopyrimidine ring and bis­ects it with a dihedral angle of 80.94 (7)°. The pyrimidine ring adopts a flattened boat conformation. In the crystal, pairs of bifurcated C—H⋯O hydrogen bonds link the mol­ecules into chains along the c axis.
doi:10.1107/S1600536812012354
PMCID: PMC3344148  PMID: 22606151
10.  14-Hy­droxy-11-[(E)-4-meth­oxy­benzyl­idene]-8-(4-meth­oxy­phen­yl)-5-thia-3,13-diaza­hepta­cyclo­[13.7.1.19,13.02,9.02,14.03,7.019,23]tetra­cosa-1(22),15(23),16,18,20-pentaen-10-one 
In the title compound, C36H32N2O4S, the piperidine ring adopts a chair conformation, while the five-membered pyrrolidine (with a C atom as the flap atom) and thia­zolidine (with the S atom as the flap atom) rings adopt envelope conformations. The naphthalene ring system makes dihedral angles of 18.82 (5) and 40.92 (5)° with the two meth­oxy-substituted benzene rings. In the crystal, centrosymmetrically-related mol­ecules are linked into dimers via pairs of C—H⋯O and C—H⋯N hydrogen bonds. An intra­molecular O—H⋯N hydrogen bond is also observed. The crystal structure is further stabilized by C—H⋯π inter­actions.
doi:10.1107/S160053681104061X
PMCID: PMC3247613  PMID: 22219918
11.  Crystal structure of (E)-2-[(2-bromopyridin-3-yl)methyl­idene]-6-meth­oxy-3,4-di­hydro­naphthalen-1(2H)-one and 3-[(E)-(6-meth­oxy-1-oxo-1,2,3,4-tetra­hydro­naphthalen-2-ylidene)meth­yl]pyridin-2(1H)-one 
The title compounds C17H14BrNO2 (I), and C17H15NO3 (II), were obtained from the reaction of 6-meth­oxy-3,4-di­hydro-2H-naphthalen-1-one and 2-bromo­nicotinaldehyde in ethanol. Compound (I) was the expected product and compound (II) was the oxidation product from air exposure.
The title compounds C17H14BrNO2, (I), and C17H15NO3, (II), were obtained from the reaction of 6-meth­oxy-3,4-di­hydro-2H-naphthalen-1-one and 2-bromo­nicotinaldehyde in ethanol. Compound (I) was the expected product and compound (II) was the oxidation product from air exposure. In the crystal structure of compound (I), there are no short contacts or hydrogen bonds. The structure does display π–π inter­actions between adjacent benzene rings and adjacent pyridyl rings. Compound (II) contains two independent mol­ecules, A and B, in the asymmetric unit; both are non-planar, the dihedral angles between the meth­oxy­benzene and 1H-pyridin-2-one mean planes being 35.07 (9)° in A and 35.28 (9)°in B. In each mol­ecule, the 1H-pyridin-2-one unit participates in inter­molecular N—H⋯O hydrogen bonding to another mol­ecule of the same type (A to A or B to B). The structure also displays π–π inter­actions between the pyridyl and the benzene rings of non-equivalent mol­ecules (viz., A to B and B to A).
doi:10.1107/S2056989016009300
PMCID: PMC4992914  PMID: 27555939
crystal structure; chalcone; 3-[(E)-(6-Meth­oxy-3,4-di­hydro­naphth-2-oyl­idene)meth­yl]-1H-pyridin-2-one and (E)-2-[(2-bromo-3-pyrid­yl)methyl­idene]-6-meth­oxy-3,4-di­hydro­naphthalen-1-one
12.  N′-[(E)-5-Bromo-2-hy­droxy-3-meth­oxy­benzyl­idene]-4-meth­oxy­benzohydrazide monohydrate 
In the title compound, C16H15BrN2O4·H2O, the hydrazide mol­ecule is nearly planar, with a largest deviation from the mean plane through the non-H atoms of 0.106 (4) Å and a dihedral angle between the benzene rings of 1.98 (16)°. This mol­ecule adopts an E conformation about the C=N bond and an intra­molecular O—H⋯N hydrogen bond increases the rigidity. In the crystal, some mol­ecules of the title hydrazide are replaced by mol­ecules of its 6-bromo isomer, and the Br atom from this admixture mol­ecule was refined to give a partial occupancy of 0.0523 (13). The hydrazide and water mol­ecules are linked through classical N—H⋯O and O—H⋯O hydrogen bonds, forming layers parallel to (110). C—H⋯π inter­actions are also present.
doi:10.1107/S1600536812033806
PMCID: PMC3470184  PMID: 23125628
13.  (E)-1-[2-Hy­droxy-4,6-bis­(meth­oxy­meth­oxy)phen­yl]-3-[3-meth­oxy-4-(meth­oxy­meth­oxy)phen­yl]prop-2-en-1-one 
The title compound, C22H26O9, crystallizes with two independent mol­ecules in the asymmetric unit in which the dihedral angles between the two benzene rings are 21.4 (2) and 5.1 (2)°. An intra­molecular O—H⋯O hydrogen bond occurs in each mol­ecule. Inter­molecular C—H⋯O hydrogen bonds stabilize the crystal structure.
doi:10.1107/S1600536811041213
PMCID: PMC3247344  PMID: 22219962
14.  3-(3-Meth­oxy­phen­yl)benzo[d]thia­zolo[3,2-a]imidazol-9-ium hydrogen sulfate 
In the title mol­ecular salt, C16H13N2OS+·HSO4 −, the thia­zolo[3,2-a]benzimidazolium ring system is roughly planar [maximum deviation = 0.046 (3) Å] and makes a dihedral angle of 58.22 (11)° with the benzene ring. The meth­oxy group is almost coplanar with its attached benzene ring [Cmeth­yl—O—C—C = −1.6 (5)°]. In the crystal, the cation is linked to the anion by a bifurcated N—H⋯(O,O) hydrogen bond, generating an R 1 2(4) ring motif. The ion pairs are then connected by a C—H⋯O hydrogen bond into inversion dimers and these dimers are further linked by O—H⋯O hydrogen bonds into an infinite tape along [100]. A π–π stacking inter­action [centroid-to-centroid distance = 3.5738 (18) Å] and a short inter­molecular contact [S⋯O = 2.830 (3) Å] are also observed.
doi:10.1107/S1600536812030541
PMCID: PMC3414329  PMID: 22904862
15.  Crystal structure of ethyl 6-chloro­methyl-2-oxo-4-(2,3,4-tri­meth­oxy­phen­yl)-1,2,3,4-tetra­hydro­pyrimidine-5-carboxyl­ate 
The di­hydro­pyrimidine ring in the title ester adopts a flattened envelope conformation. An intra­molecular C—H⋯O hydrogen bond generates an S(6) ring. Mol­ecules are linked via pairs of N—H⋯O hydrogen bonds, forming inversion dimers.
In the title compound, C17H21ClN2O6, the di­hydro­pyrimidine ring adopts a flattened envelope conformation, with the sp 3-hybridized C atom forming the flap. The dihedral angle between the least-squares planes of the benzene and di­hydro­pyrimidine rings is 88.09 (6)°. An intra­molecular C—H⋯O hydrogen bond generates an S(6) ring. In the crystal, mol­ecules are linked via pairs of N—H⋯O hydrogen bonds, forming inversion dimers with an R 2 2(8) ring motif, and the dimers are linked via further pairs of N—H⋯O hydrogen bonds, forming R 2 2(14) rings and chains of mol­ecules along [111]. Pairs of inversion-related chains are linked via weak C—H⋯π inter­actions.
doi:10.1107/S2056989015011688
PMCID: PMC4518964  PMID: 26279876
crystal structure; conformation; di­hydro­pyrimidine; ring motif; C—H⋯π inter­actions
16.  Crystal structure of ethyl 6-methyl-2-oxo-4-(3,4,5-tri­meth­oxy­phen­yl)-1,2,3,4-tetra­hydro­pyrimidine-5-carboxyl­ate 
In the title compound, C17H22N2O6, the di­hydro­pyrimidine ring adopts a flattened boat conformation. The dihedral angle between the benzene ring and the mean plane of the di­hydro­pyrimidine ring is 75.25 (6)°. In the crystal, mol­ecules are linked via pairs of N—H⋯O hydrogen bonds, forming inversion dimers with an R 2 2(8) ring motif which are linked through N—H⋯O and weak C—H⋯O hydrogen bonds. These, together with π–π ring inter­actions [centroid–centroid distance = 3.7965 (10) Å], give an overall three-dimensional structure.
doi:10.1107/S2056989015003576
PMCID: PMC4350754  PMID: 25844251
crystal structure; pyrimidine; hydrogen bonds; centrosymmetric dimer
17.  Crystal structure of ethyl 5-(3-fluoro­phen­yl)-2-[(4-fluoro­phen­yl)methyl­idene]-7-methyl-3-oxo-2H,3H,5H-[1,3]thia­zolo[3,2-a]pyrimidine-6-carboxyl­ate 
In the title mol­ecule, C23H18F2N2O3S, the pyrimidine ring is in a half-chair conformation and the 3-fluoro­phenyl group is in the axial position. The thia­zole ring (r.m.s. deviation = 0.0252 Å) forms dihedral angles of 84.8 (7) and 9.6 (7)° with the 3-fluoro-substituted and 4-fluoro-substituted benzene rings, respectively. In the crystal, weak C—H⋯F and C—H⋯O hydrogen bonds connect mol­ecules, forming zigzag chains along the b axis. In addition π–π stacking inter­actions with a centroid–centroid distance of 3.7633 (9) Å connect these chains into ladders via inversion-related 4-fluoro­phenyl groups.
doi:10.1107/S1600536814023010
PMCID: PMC4257247  PMID: 25484821
crystal structure; pyrimidine; thia­zole; hydrogen bonds; π–π stacking inter­actions
18.  Ethyl 3-acetyl-4-(3-meth­oxy­phen­yl)-6-methyl-2-sulfanyl­idene-1,2,3,4-tetra­hydro­pyrimidine-5-carboxyl­ate 
In the title compound, C17H20N2O4S, the aryl ring is positioned perpendicular to the dihydro­pyrimidine ring, the dihedral angle between the ring planes being 77.48 (9)°. The carboxyl­ate and methyl groups are in a cis conformation with respect to the C=C bond. The dihydro­pyrimidine ring adopts a twist-boat conformation. The crystal structure is stabilized by N—H⋯O and C—H⋯O inter­actions, the former resulting in mol­ecular chains along the b axis and the latter forming inversion dimers.
doi:10.1107/S1600536812017679
PMCID: PMC3344654  PMID: 22590416
19.  N′-[(E)-2-Hy­droxy-5-meth­oxy­benzyl­idene]-2-meth­oxy­benzohydrazide 
The mol­ecule of the title compound, C16H16N2O4, adopts an E conformation about the azomethine C=N double bond. The dihedral angle formed by the benzene rings is 18.88 (9)°. The mol­ecular conformation is stabilized by an intra­molecular O—H⋯N hydrogen bond, which forms an S(6) ring. In the crystal, the mol­ecules are linked into chains parallel to [001] by N—H⋯O hydrogen bonds. The chains are further connected into a three-dimensional network by π–π stacking inter­actions with centroid–centroid distances of 3.6538 (10) and 3.8995 (11) Å.
doi:10.1107/S1600536812042389
PMCID: PMC3588809  PMID: 23468774
20.  (E)-N′-(3-Hy­droxy-4-meth­oxy­benzyl­idene)-4-meth­oxy­benzohydrazide 
The title mol­ecule, a benzohydrazide derivative, C16H16N2O4, is twisted with a dihedral angle of 69.97 (5)° between the two benzene rings. An intra­molecular O—H⋯O hydrogen bond generates an S(5) ring motif. In the crystal, mol­ecules are linked by N—H⋯O and weak C—H⋯O hydrogen bonds into a chain along the c axis. C—H⋯π inter­actions are also present.
doi:10.1107/S1600536811048240
PMCID: PMC3239014  PMID: 22199863
21.  (E)-3-(8-Benz­yloxy-2,3-dihydro-1,4-benzodioxin-6-yl)-1-[2-hy­droxy-4,6-bis­(meth­oxy­meth­oxy)phen­yl]prop-2-en-1-one 
In the title mol­ecule, C28H28O9, the phenol and the benzene rings adjacent to the α,β-unsaturated ketone unit are inclined at 9.15 (13)° to each other. The terminal phenyl ring is oriented with respect to the phenol ring at a dihedral angle of 85.88 (13)°. In the crystal, the methyl­ene C atoms of the dihydro­dioxine ring are disordered over two sites with an occupancy ratio of 0.463 (18):0.537 (18), and both disordered components of the dihydro­dioxine ring adopt twisted-chair conformations. An intra­molecular O—H⋯O hydrogen bond and weak inter­molecular C—H⋯O hydrogen bonds are present in the crystal structure.
doi:10.1107/S160053681100924X
PMCID: PMC3100013  PMID: 21754185
22.  1-[4-(Difluoro­meth­oxy)phen­yl]-N-(3,4-dimeth­oxy­phen­yl)-1H-1,2,4-triazole-3-carboxamide 
Two crystallographically independent mol­ecules, A and B, with similar conformations are present in the asymmetric unit of the title compound, C18H16F2N4O4. In mol­ecule A, the plane of the 1,2,4-triazole ring is tilted relative of the 4-difluoro­meth­oxy-substituted and the 3,4-dimeth­oxy-substituted benzene rings by 6.5 (2) and 16.4 (1)°, respectively. The –CHF2 group is twisted away from the plane of the benzene ring, with a dihedral angle between the O—C bond of the OCHF2 group and the plane of the adjacent phenyl ring of 38.6 (3)°. The corresponding parameters for mol­ecule B are 7.7 (1), 9.5 (2) and 25.2 (2)°. In both mol­ecules, the conformations are stabilized by intra­molecular N—H⋯N and C—H⋯O hydrogen bonds. There are also C—H⋯π contacts between the methyl groups and the benzene rings, and π–π stacking inter­actions between the benzene rings of adjacent parallel A mol­ecules [centroid–centroid distance = 3.8942 (17) Å]. π–π inter­actions are also observed between the triazole ring and one of the benzene rings of parallel B mol­ecules [centroid–centroid distance = 3.7055 (16) Å].
doi:10.1107/S1600536810029661
PMCID: PMC3007844  PMID: 21588626
23.  4-(3-Fluoro-4-meth­oxy­phen­yl)-1-(4-meth­oxy­phen­yl)-5-(3,4,5-trimeth­oxy­phen­yl)-1H-imidazole 
In the title mol­ecule, C26H25FN2O5, the fluoro­meth­oxy-, meth­oxy- and trimeth­oxy-substituted benzene rings form dihedral angles of 12.65 (2), 84.15 (2) and 55.67 (2)°, respectively, with the imidazole ring. The crystal structure is stabilized weak inter­molecular C—H⋯F and C—H⋯O hydrogen bonds.
doi:10.1107/S160053681004465X
PMCID: PMC3011382  PMID: 21589391
24.  1-[(Cyclo­propyl­meth­oxy)meth­yl]-6-(3,4-dimeth­oxy­benzyl)-5-ethyl-1,2,3,4-tetra­hydro­pyrimidine-2,4-dione ethanol hemisolvate 
The asymmetric unit of the compound, C20H26N2O5·0.5C2H5OH, consists of two tetra­hydro­pyrimidine-2,4-dione mol­ecules and an ethanol mol­ecule. The pyrimidine rings are nearly planar (r.m.s. deviation = 0.006 Å in one mol­ecule and 0.009 Å in the other); the C atom at the 5-position deviates by 0.083 (3) Å [0.064 (3) Å in the second mol­ecule] from the mean plane and the C atom at the 6-position by 0.034 (3) Å [0.082 (3) Å in the second mol­ecule]. In each mol­ecule, the benzene ring is nearly perpendicular to the pyrimidine ring, the dihedral angle is 88.51 (8)° in one mol­ecule and 84.70 (8)° in the other. The amino group of each tetra­hydro­pyrimidine-2,4-dione mol­ecule is a hydrogen-bond donor to the exocyclic O atom at the 2-position of an adjacent mol­ecule, the hydrogen bond generating an inversion dimer in each case. The ethanol mol­ecule forms a hydrogen bond to the meth­oxy O atom of one of two independent mol­ecules.
doi:10.1107/S1600536811055693
PMCID: PMC3275033  PMID: 22346978
25.  4-[3-(Phen­oxy­meth­yl)-7H-1,2,4-triazolo[3,4-b][1,3,4]thia­diazin-6-yl]-3-(p-tol­yl)sydnone 
In the title triazolothia­diazine derivative, C20H16N6O3S {systematic name: 3-(4-methyl­phen­yl)-4-[3-(phen­oxy­meth­yl)-7H-1,2,4-triazolo[3,4-b][1,3,4]thia­diazin-6-yl]-1,2,3-oxadiazol-3-ium-5-olate}, an S(6) ring motif is generated by an intra­molecular C—H⋯O hydrogen bond. The 3,6-dihydro-1,3,4-thia­diazine ring adopts a twist-boat conformation. The dihedral angle between the 1,2,3-oxadiazole and 1,2,4-triazole rings is 46.45 (14)°. The 1,2,3-oxadiazole ring is inclined at dihedral angle of 59.49 (13)° with respect to the benzene ring attached to it. In the crystal structure, inter­molecular C—H⋯O and C—H⋯N hydrogen bonds link neighbouring mol­ecules into two-mol­ecule-thick arrays parallel to the bc plane. A short S⋯O inter­action [2.9565 (19) Å] also occurs.
doi:10.1107/S1600536810029910
PMCID: PMC3007409  PMID: 21588457

Results 1-25 (299441)