Browsing by Author "Manavendra K. Singh"

Now showing 1 - 6 of 6

1-Prop-2-ynyl-1H-benzimidazol-2-amine
(2011) Alka Agarwal; Manavendra K. Singh; Satish K. Awasthi
In the title compound, C10H9N3, the benzimidazol-2-amine and CH2 -C≡CH units are not coplanar, with a dihedral angle of 60.36°between their mean planes. The crystal structure is stabilized by intermolecular N-H⋯N hydrogen bonding and π-π interactions [centroid-centroid distances 3.677 (1) and 3.580 (1) Å], assembling the molecules into a supra-molecular structure with a three-dimensional network.
2-(4-Chlorophenyl)chromen-4-one
(2011) Shailja Singh; Manavendra K. Singh; Alka Agarwal; Satish K. Awasthi
The title compound, C15H9ClO2, is a synthetic flavonoid obtained by the cyclization of 3-(4-chloro-phen-yl)-1-(2-hy- droxy-phen-yl)prop-2-en-1-one. The 4-chloro-phenyl ring is twisted at an angle of 11.54°with respect to the chromen-4-one skeleton. In the crystal, pairs of molecules are interconnected by weak Cl⋯Cl interactions [3.3089 (10) Å] forming dimmers which are further peripherally connected through intermolecular C-H⋯O hydrogen bonds..
(2E)-1-(4-Amino-phen-yl)-3-(2,4-dichloro-phen-yl)prop-2-en-1-one
(2011) Shailja Singh; Manavendra K. Singh; Alka Agarwal; Firasat Hussain; Satish K. Awasthi
The title compound, C 15H 11C l2NO, is approximately planar (r.m.s. deviation = 0.062 Å) and contains a single C=C double bond in a trans (E) configuration. The crystal packing is stabilized by intermolecular N - H⋯N and N - H⋯O inter-molecular hydrogen bonding. © Singh et al. 2011.
Benzyl N-(3-chloro-4-fluorophenyl)-carbamate
(2011) Manavendra K. Singh; Alka Agarwal; Satish K. Awasthi
The title compound, C14H11ClFNO2, the phenyl ring (A), the chlorofluorophenyl ring (B) and the central ketone O/C/O group (C) are not coplanar, with dihedral angles B/C = 31.6 (2), A/B = 21.3 (2) and A/C = 50.1 (2)°. The crystal packing is stabilized byN-H⋯O and C-H⋯O interactions.
Design, synthesis and antimicrobial activity of novel benzothiazole analogs
(2013) Manavendra K. Singh; Ragini Tilak; Gopal Nath; Satish K. Awasthi; Alka Agarwal
In an attempt to design and synthesize a new class of antimicrobials, dialkyne substituted 2-aminobenzothiazole was reacted with various substituted aryl azides to generate a small library of 20 compounds (3a-t) by click chemistry. Structures of the newly synthesized compounds were established on the basis of spectral data. These compounds were screened for their antibacterial activity against Gram+ bacteria (Staphylococcus aureus and Enterococcus faecalis), Gram- bacteria (Salmonella typhi, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Shigella boydii) and antifungal activity against Candida tropicalis, Candida albicans, Candida krusei, Cryptococcus neoformans) as well as molds (Aspergillus niger, Aspergillus fumigatus). The compound 3e showed maximum potency against all Gram+/gram- bacterial strains with MIC value 3.12 μg/ml, which is two fold more active as compared to standard drug ciprofloxacin (MIC 6.25 μg/ml). However, all compounds were found ineffective against S. boydii (clinical isolate). Further, only one compound 3n was found to be the most active against all fungal strains with MIC value in the range of 1.56 μg/ml-12.5 μg/ml while the remaining compounds showed moderate to weak antifungal activity. © 2013 Elsevier Masson SAS. All rights reserved.
Tert-Butyl N-{2-[bis-(prop-2-yn-1yl)amino]phenyl}carbamate
(2011) Manavendra K. Singh; Alka Agarwal; Charu Mahawar; Satish K. Awasthi
In the crystal of the title compound, C17H20N 2O2, the molecules are linked by C-H⋯O interactions. Intra-molecular C-H⋯O and N-H⋯N hydrogen bonds also occur.