Pralav Bhatt

Synthesis and pharmacological evaluation of novel 1-(piperidin-4-yl)-1H-benzo[d]imidazol-2(3H)-one derivatives as potential antimicrobial agents

Novel compounds of biological interest were synthesized by in situ reduction of Schiff’s base of 5,6-dimethoxy indanone and 1-(piperidin-4-yl)-1H-benzo[d]imidazol-2(3H)-one in the presence of Ti(OiPr)4 and NaBH3CN. Further alkylation using different alkyl/aryl halides in the presence of NaH in DMF gave a series of novel compounds. A formation of newly synthesized compounds was confirmed on the basis of their spectral and elemental analysis. Further these compounds were screened for their antimicrobial activity and found to have promising antibacterial and antifungal activity.

Ethyl 2-(3,5-dimethyl-1,1-dioxo-2H-1λ6,2,6-thia­diazin-4-yl)benzoate

In the title compound, C14H16N2O4S, the thiadiazine ring is in a half-boat conformation. The aromatic ring deviates from the plane of this moiety at an angle of 74.6 (2)°. The structure displays intermolecular N—H⋯O hydrogen bonding [N⋯O = 2.8157 (16) Å], creating ribbons along the [010] axis. There are also weak C—H⋯O interactions in the crystal but no π–π stacking.

2-(3,5-Dimethyl-1,1-dioxo-2H-1λ6,2,6-thia­diazin-4-yl)benzoic acid

In the title molecule, C12H12N2O4S, the S atom of the thiadiazine ring deviates by 0.5104 (4) Å from the mean plane of the other five atoms [largest deviation = 0.0623 (15) Å] giving a slightly distorted sofa conformation. The carboxy H atom was refined as disordered over two sets of sites with refined occupancies of 0.58 (2) and 0.48 (2). This corresponds to rotational disorder of the C=O and O—H groups about the attached C—C bond. In the crystal, O—H⋯O and N—H⋯O hydrogen bonds connect the molecules into chains along [110].

N-Benzyl-5-(dimethyl-amino)-naphthalene-1-sulfonamide.

The structure of the title compound, C19H20N2O2S, displays intermolecular N—H⋯O hydrogen bonding, which generates inversion dimers. There is no π–π stacking in the crystal structure. The dihedral angle between the phenyl ring and naphthalene ring system is 59.16 (11)°.

Crystal structure of potassium 4-(2-carboxyphenyl)-3,5-dimethyl-1,2,6- thiadiazin-2-ide 1,1-dioxide monohydrate, C12H13KN2O5S

Abstract C12H13KN2O5S, monoclinic, P21/c (no. 14), a = 15.8681(4) Å, b = 7.2173(2) Å, c = 12.8527(4) Å, β = 109.6260(10)°, V = 1386.4 Å3, Z = 4, Rgt(F) = 0.0248, wRref(F2) = 0.0858, T = 173 K.

Crystal structure of (S)-tert-butyl 3-carbamothioyl-3,4-dihydroisoquinoline- 2(1H)-carboxylate, C63H86N8O9S4

C63H86N8O9S4, tetragonal, I4 (no. 79), a = 22.5939(8) Å, c = 6.6576(4) Å, V = 3398.6(3) Å, Z = 2, Rgt(F) = 0.0351, wRref(F ) = 0.0977, T = 173 K.

(S)-4-Phenyl-2-(1,2,3,4-tetra-hydro-isoquinolin-3-yl)-1,3-thia-zole.

In the title compound, C18H16N2S, the N-containing ring adopts a half-chair configuration. The crystal packing features C—H⋯N contacts. There is no π–π stacking within the crystal structure.