Ramaiyan Manikannan

Pyrazole derivatives from azines of substituted phenacyl aryl/cyclohexyl sulfides and their antimycobacterial activity

Azines derived from substituted phenacyl aryl/cyclohexyl sulfide on treatment with excess phosphorous oxychloride in N,N-dimethylformamide have been found to yield two isomeric pyrazoles in each case. A plausible mechanism has been suggested for the formation of the products. The antimycobacterial activity of the isomeric compounds has been tested against Mycobacterium tuberculosis (MTB).

Selective one-pot multicomponent synthesis and anti-tubercular evaluation of 5-(aryl/cyclohexylsulfanyl)-2-alkoxy-4,6-diarylnicotinonitriles

A new set of highly substituted pyridine derivatives has been synthesized by a product selective four component reaction of aryl aldehyde, malononitrile and 2-aryl/cyclohexylsulfanyl-1-aryl-1-ethanones in presence of sodium hydroxide in methyl/ethyl alcohol. Among the compounds, 4,6-bis(4-chlorophenyl)-5-[(4-chlorophenyl)sulfanyl]-2-methoxynicotinonitrile (4n) inhibited Mycobacterium tuberculosis (MTB) with minimum inhibitory concentration (MIC) of 3.1 microM and was more potent than ethambutol and pyrazinamide.

3,3′-(p-Phenyl­ene)bis­(3,4-dihydro-2H-1,3-benzoxazine)

Molecules of the title compound, C22H20N2O2, are situated on crystallographic centres of symmetry. The oxazinane ring adopts a sofa conformation. Molecules are linked into cyclic centrosymmetric dimers via C—H⋯O hydrogen bonds with the motif R 2 2(6). In addition to the C—H⋯O interactions, the crystal structure is also stabilized by C—H⋯π interactions.

Synthesis of Highly Substituted N-Hydroxy Piperidine via Intramolecular Reductive Cyclization of 1-Keto-5-ketoxime

Abstract Diasteroselective synthesis of highly substituted N-hydroxypiperidine was achieved by an intramolecular reductive cyclization of monoxime (2) of the 1,5-diketone (1), generated from 2-(cyclohexylthio)-1-phenylethanone and arylaldehyde, using NaBH3CN. The major product N-hydroxypiperidine (3) has been found to be racemate of a single diastereomer. GRAPHICAL ABSTRACT

1-(2,4-Dinitro­phen­yl)-3-phenyl-4-phenyl­sulfanyl-1H-pyrazole

In the title molecule, C21H14N4O4S, the pyrazole ring forms dihedral angles of 45.6 (1), 87.7 (1) and 27.4 (1)° with the phenyl, sulfur-substituted benzene and nitro-substituted benzene rings, respectively. In the crystal, molecules are connected by weak C—H⋯O and C—H⋯N hydrogen bonds into layers parallel to (010).

Synthesis and Conformational Features of 4-(Cyclohexylsulfanyl)-1-(2,4-dinitrophenyl)-3-aryl-1H-pyrazole

Abstract A set of new 4-(cyclohexylsulfanyl)-1,3-diaryl-1H-pyrazoles has been synthesized using Vilsmeiers reagent. It is found that 4-(cyclohexylsulfanyl)-1-(2,4-dinitrophenyl)-3-(4-methoxyphenyl)-1H-pyrazole exists with the arylthio group in the equatorial position of the cyclohexyl group in solution, whereas it has the arylthio group in the axial position of the cyclohexyl group in crystal state as evidenced by NMR and single-crystal x-ray analysis respectively.

(E)-3-(4-Chloro-phen-yl)-3-[3-(4-chloro-phen-yl)-1H-pyrazol-1-yl]prop-2-enal.

In the title compound, C18H12Cl2N2O, the pyrazole ring is almost planar [r.m.s. deviation = 0.002 Å] while the two chlorophenyl rings are twisted out from the plane of the pyrazole ring, making dihedral angles of 5.3 (1) and 65.34 (4)°. In the crystal, centrosymmetric R 2 2(24) dimers are formed about crystallographic inversion centres through a pair of C—H⋯Cl interactions. These dimers are further linked through a C—H⋯O hydrogen bond, forming a C(8) chain extending along the a axis. C—H⋯π interactions are also observed.

3-Cyclo­hexyl­sulfan­yl-2-(4-methyl­phen­yl)-5,7-dinitro-1H-indole

In the title compound, C21H21N3O4S, the cyclohexane ring adopts a chair conformation. The nitro and methylphenyl groups are all coplanar with the indole ring system. Intramolecular N—H⋯O and C—H⋯S hydrogen bonds generate S(6) ring motifs. The molecules form R 2 2(20) centrosymmetric dimers via intermolecular C—H⋯O hydrogen bonds. A short O⋯O contact [2.842 (2) Å] is observed in the dimer.

Synthesis and characterization of 5-heteroarylsulfanyl-4-aryl- 1,2,3-selena/thiadiazoles

AbstractSynthesis and spectral characterization of 2-methyl-5-[(4-aryl-1,2,3-selenadiazol-5-yl)sulfanyl]-1,3,4-thiadiazoles, 5-[4-aryl-1,2,3-selenadiazol-5-yl]sulfanyl-1-phenyl-1H-1,2,3,4-tetraazoles, 4-aryl-5-[(5-methyl-1,3,4-thiadiazol-2-yl)sulfanyl]-1,2,3-thiadiazole and 5-[4-aryl-1,2,3-thiadiazol-5-yl]sulfanyl-1-phenyl-1H-1,2,3,4-tetraazole have been reported. Graphical AbstractSynthesis and spectral characterization of 2-methyl-5-[(4-aryl-1,2,3-selenadiazol-5-yl)sulfanyl]-1,3,4-thiadiazoles, 5-[4-aryl-1,2,3-selenadiazol-5-yl]sulfanyl-1-phenyl-1H-1,2,3,4-tetraazoles, 4-aryl-5-[(5-methyl-1,3,4-thiadiazol-2-yl)sulfanyl]-1,2,3-thiadiazole and 5-[4-aryl-1,2,3-thiadiazol-5-yl] sulfanyl-1-phenyl-1H-1,2,3,4-tetraazole have been reported.

(E)-3-Phenyl-3-(3-phenyl-1H-1-pyrazol-yl)-2-propenal.

In the title compound C18H14N2O, the pendant rings make dihedral angles of 66.1 (1)° and 13.9 (1) with the central ring. In the crystal, two molecules form a cyclic centrosymmetric R 2 2(22) dimer through pairs of C—H⋯O bonds. These dimers are further connected into zigzag chains extending along the b axis through C—H⋯π and C—H⋯O interactions.