[2-(1,3-Benzothia-zol-2-ylmeth-oxy)-5-bromo-phen-yl](4-chloro-phen-yl)methanone

Recent advances in the synthesis of new benzothiazole based anti-tubercular compounds

This review highlights the recent synthetic developments of benzothiazole based anti-tubercular compounds and their in vitro and in vivo activity. The inhibitory concentrations of the newly synthesized molecules were compared with the standard reference drugs. The better inhibition potency was found in new benzothiazole derivatives against M. tuberculosis. Synthesis of benzothiazole derivatives was achieved through various synthetic pathways including diazo-coupling, Knoevenagel condensation, Biginelli reaction, molecular hybridization techniques, microwave irradiation, one-pot multicomponent reactions etc. Other than recent synthetic developments, mechanism of resistance of anti-TB drugs is also incorporated in this review. Structure activity relationships of the new benzothiazole derivatives along with the molecular docking studies of selected compounds have been discussed against the target DprE1 in search of a potent inhibitor with enhanced anti-tubercular activity.

Benzothiazole analogs as potential anti-TB agents: computational input and molecular dynamics

Biotin is very important for the survival of Mycobacterium tuberculosis. 7,8-Diamino pelargonic acid aminotransaminase (DAPA) is a transaminase enzyme involved in the biosynthesis of biotin. The benzothiazole title compounds were investigated for their in vitro anti-tubercular activity against two tubercular strains: H37Rv (ATCC 25,177) and MDR-MTB (multidrug-resistant M. tuberculosis, resistant to isoniazid, rifampicin, and ethambutol) by an agar incorporation method. The possible binding mode and predicted affinity were computed using a molecular docking study. Among the synthesized compounds in the series, the title compound {2-(benzo[d]thiazol-2-yl-methoxy)-5-fluorophenyl}-(4-chlorophenyl)-methanone was found to exhibit significant activity with minimum inhibitory concentrations of 1 μg/mL and 2 μg/mL against H37Rv and MDR-MTB, respectively; this compound showed the highest binding affinity (-24.75 kcal/mol) as well.

{2-[(1,3-Benzo-thia-zol-2-yl)meth-oxy]-5-chloro-phen-yl}(4-chloro-phen-yl)methan-one

In the title compound, C₂₁H₁₃Cl₂NO₂S, the benzo­thia­zole ring makes dihedral angles of 0.94 (1) and 70.65 (5)° with the 4-chloro­phenyl­methanone unit and the 5-chloro­phenyl ring, respectively. The dihedral angle between the 4-chloro­phenyl­methanone unit and the 5-chloro­phenyl ring is 66.20 (5)°. The crystal structure consists of dimeric units generated by C—H⋯N hydrogen bonds, further linked by C—H⋯O and C—H⋯π inter­actions, leading to a three-dimensional network.

{2-[(1,3-Benzo-thia-zol-2-yl)meth-oxy]-5-fluoro-phen-yl}(4-chloro-phen-yl)methanone

The asymmetric unit of the title compound, C₂₁H₁₃ClFNO₂S, contains two independent mol­ecules with similar conformations. In the mol­ecules, the thia­zole ring is essentially planar [maximum atomic deviations = 0.014 (4) and 0.023 (5) Å] and is oriented with respect to the fluoro­phenyl ring and chloro­phenyl rings at 9.96 (18) and 70.39 (18)° in one mol­ecule and at 7.50 (18) and 68.43 (18)° in the other; the dihedral angles between the fluoro­phenyl and chloro­phenyl rings are 64.9 (2) and 64.6 (2)°, respectively. Inter­molecular C—H⋯O and C—H⋯F hydrogen bonds stabilize the three-dimensional supra­molecular architecture. Weak C—H⋯π and π–π inter­actions [centroid–centroid distance = 3.877 (3) Å] lead to a criss-cross mol­ecular packing along the c axis.