22307-44-4Relevant articles and documents
Catalytic N-formylation for synthesis of 6-substituted-2-benzothiazolylimino-5-piperazinyl-4-thiazolidinone antimicrobial agents
Patel, Rahul V.,Park, Se Won
, p. 5599 - 5609 (2015/07/08)
A new class of piperazine-based 2-benzothiazolylimino-4-thiazolidinones has been efficiently prepared via highly accelerated N-formylation of N-isopropylpiperazine by the use of a mild heterogeneous catalyst, sulfated tungstate. Heterocyclization of N-(benzo[d]thiazol-2-yl)-2-chloroacetamides (3a-j) by use of NH4SCN in ethanol under reflux efficiently furnished the intermediates 2-benzothiazolyliminothiazolidin-4-ones (4a-j). These were treated with 4-isopropylpiperazine-1-carbaldehyde (2) to prepare the final products 5a-j. The structures of the new derivatives were confirmed by elemental analysis and use of spectroscopic data (FTIR and 1H NMR). Their pharmacological potential as promising antimicrobial agents was determined in vitro against bacteria and a fungus; the lowest minimum inhibitory concentrations (MIC) observed were in the range 4-8 μg/mL.
In vitro biological investigations of novel piperazine based heterocycles
Chhatriwala, Nirmal M.,Patel, Amit B.,Patel, Rahul V.,Kumari, Premlata
, p. 611 - 616 (2015/02/02)
Eleven N.phenyl- and 11 N.benzothiazolyl-2-(4-(2,3,4-trimethoxybenzyl)piperazin-1-yl)acetamides have been synthesised by a simple and efficient method. The 22 novel compounds were tested for their in vitro biological efficacy against two Grampositive bacteria, three Gram-negative bacteria, two fungi and Mycobacterium tuberculosis H37Rv. The bioassay results revealed that the majority of the N.benzothiazole-substituted piperazine derivatives exhibited moderate to good bioefficacies with encouraging MICs. The influence of the presence or absence of various electron-withdrawing or -donating functional groups on the aryl acetamide moiety on the different bioassay results is discussed.
Discovery of the highly potent Fluoroquinolone-based Benzothiazolyl-4- thiazolidinone hybrids as antibacterials
Patel, Rahul V.,Park, Se Won
, p. 123 - 129 (2014/07/07)
A new series of fluoroquinolone-based benzothiazolyl-4-thiazolidinone hybrids has been yielded via sulfated tungstate-promoted highly accelerated N-formylation at a piperazine residue of ciprofloxacin and norfloxacin entities. The formylated fluoroquinolone moieties were then coupled with substituted 2-aminobenzothiazoles, which were generated from their respective para-substituted amines to form corresponding Schiff base intermediates. The Schiff bases were then treated with thioglycolic acid to equip a new class of 4-thiazolidinones to be analyzed for their antibacterial effects against two Gram-positive (Staphylococcus aureus and Bacillus subtilis) and two Gram-negative (Escherichia coli and Pseudomonas aeruginosa) bacterial strains and were found highly potent with lowest Minimum inhibitory concentrations (MIC), 1-2 μg/mL, that is, more potent than control drugs ciprofloxacin (3.12-6.25 μg/mL). Initial outcomes provided for these novel molecular systems will aid researchers to design and develop new antibacterial drugs. The structural assignments of the new products were done on the basis of FT-IR, 1H NMR and 13C NMR spectroscopy, and elemental analysis. A truly rationalized design of a new class of 4-thiazolidinones revealed potent antibacterial efficacies with lowest MICs 1-2 μg/mL when compared to control drug ciprofloxacin at 3.12-6.25 μg/mL. Combination of electron-withdrawing substituent on the benzothiazole ring and norfloxacin entity furnished anti-Gram-positive effects, as well as combination of electron-releasing substituent with ciprofloxacin entity furnished anti-Gram-negative potency. Two thiazole rings positively enhanced the potency of the final scaffolds.
