Synthesis and crystal structure of ethyl 2-​{5-​[2-​(2,​6-​dichlorophenylamino)​benzyl]​-​4-​p-​tolyl-​4H-​1,​2,​4-​triazol-​3-​ylthio}​acetate

The compound 2-{5-[2-(2,6-dichlorophenylamino)benzyl]-4-p-tolyl-4H-1,2,4-triazol-3-ylthio}acetate has been prepared and characterized by IR, 1H NMR, 13C NMR and mass spectra. The crystal and molecular structure were further confirmed using single crystal X-ray diffraction. The crystal structure has been found to be stabilized by intermolecular C–H···O interaction generating bifurcated hydrogen bonds whereas the C–H···N interactions generate chain of molecules. The intramolecular N–H···N hydrogen bond forms a ring with S(7) graph-set motif

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

Methyl 2-(2-bromo­benzyl­idene)-5-(4-hy­droxy­phen­yl)-7-methyl-3-oxo-2,3-dihydro-5H-1,3-thia­zolo[3,2-a]pyrimidine-6-carboxyl­ate

In the title compound, C22H17BrN2O4S, the central dihydropyrimidine ring, with a chiral C atom, is significantly puckered and adopts a half-chair conformation with the chiral C atom displaced from the mean plane of the remaining ring atoms by 0.305 (6) Å. The hydroxy-phenyl ring is positioned axially to the pyrimidine ring and almost bisects it, the dihedral angle between the mean-planes of the two rings being 89.78 (12)°. The meth­oxy­carbonyl group is disordered over two sites with an occupancy ratio of 0.568 (5):0.432 (5), resulting in a major and a minor conformer. In the crystal, O—H⋯N and C—H⋯S inter­actions result in sheets along the c axis. The supra­molecular assembly is stabilized by π–π stacking inter­actions between the 2-bromo­benzyl­idene and thia­zolopyrimidine rings [centroid–centroid distance = 3.632 (1) Å]. In addition, C—H⋯π inter­actions are also observed in the crystal structure

Synthesis, spectroscopy and X-​ray crystal structure of 9-​methyl-​3-​(2-​thienyl)​thieno[3,​2-​e]​[1,​2,​4]​triazolo[4,​3-​c]​pyrimidine-​8-​carboxylic acid ethyl ester

The synthesis of the target compd. was achieved by a reaction of 4-​cyano-​5-​[(ethoxymethylene)​amino]​-​3-​methyl-​2-​thiophenecarboxylic acid Et ester with 2-​thiophenecarboxylic acid hydrazide. The product thus obtained was confirmed by elemental anal., IR, 1H-​NMR, 13C-​NMR and X-​ray crystal structure anal. [i.e., 9-​methyl-​3-​(2-​thienyl)​thieno[3,​2-​e]​-​1,​2,​4-​triazolo[4,​3-​c]​pyrimidine-​8-​carboxylic acid Et ester]​. There are two independent mols. in the asym. unit exhibiting intermol. C-​H...N, C-​H...O interactions with addnl. π-​π interaction that further helps in stabilizing the supramol. structure

2-Phenyl-8,9,10,11-tetra­hydro-1-benzo­thieno[3,2-e][1,2,4]triazolo[1,5-c]pyrimidine

In the title compound, C17H14N4S, the benzothieno moiety is fused at one end of the pyramidine ring while the triazole ring with a phenyl substituent is fused at the other side. The triazole ring is almost planar [maximum deviation = 0.0028 (3) Å] while the cyclo­hexane ring adopts a half-chair conformation. In the crystal, pairs of inter­molecular C—H⋯N hydrogen bonds form centrosymmetric head-to-head dimers, corresponding to an R 2 2(8) graph-set motif. Further C—H⋯N inter­actions generate a zigzag chain of mol­ecules along the c axis. The supra­molecular assembly is consolidated by π–π stacking inter­actions [centroid–centroid distance = 3.445 (4) Å]

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

2-[4-(Trifluoromethoxy)phenyl]-1H-benzimidazole

In the title compound, C14H9F3N2O, the best planes of the benzimidazole group and benzene ring form a dihedral angle of 26.68 (3)°. In the crystal, N—H...N hydrogen bonds link the molecules into infinite chains parallel to the c axis. Stacking interactions between the benzimidazole groups [centroid–centroid distance = 3.594 (5) Å] assemble the molecules into layers parallel to (100). The trifluoromethyl group is disordered over three sets of sites with site-occupancy factors of 0.787 (4), 0.107 (7) and 0.106 (7)

2-(3,4-Difluorophenyl)-1H-benzimidazole

In the title molecule, C13H8F2N2, the dihedral angle between the benzimidazole ring system and the difluoro-substituted benzene ring is 30.0 (1)°. In the crystal, molecules are linked by N—H...N hydrogen bonds, forming chains along [010]. In addition, weak C—H...F hydrogen bonds connect chains into a two-dimensional network parallel to (001). A weak C—H...π interaction is observed between an H atom of the benzimidazole ring sytem and the π system of the difluoro-substituted benzene ring

The prevalence of dentin hypersensitivity among adult patients in Bangalore City

Objective: The aim of the study was to determine the Prevalence of Dentin Hypersensitivity (DH) among adult patients in Bangalore city, India and to suggest most appropriate clinical method to diagnose dentin hypersensitivity. Methodology: All adult patients attending the outpatient Department of the Oxford Dental College in Bangalore were considered for the study. Patients with sensitivity were subjected to detailed intra oral examination and interviewed using a structured questionnaire. All the teeth were tested for Evidence of dentin hypersensitivity by the use of air blast & water from the air-water jet syringe and by scratching the suspected tooth surfaces with a dental probe. The responses of each tooth ofthe subjects were recorded on the visual analog scale (VAS). Results: An overall prevalence of dentin hypersensitivity was 6.4%. About 86.8% patients perceived their experience of dentin hypersensitivity as sharp and 13.2% patients experienced it as dull, cold acted as the common stimulant. Premolars and molars were the most commonly affected teeth, maxillary arch have higher number of sensitive teeth compared to mandibular arch. DH was more elicited on the occlusal surface followed by cervical surfaces of the teeth. The perceived response of DH on VAS scale showed a significant difference among the methods (p<0.001) with probe method eliciting the highest response on the VAS scale followed by the air for 10 seconds. Conclusion: The prevalence of DH among adult population of Bangalore city was 6.4%. Probe was considered as most appropriate method to diagnose Dentin Hypersensitivity