RESUMO
A greener water mediated protocol for the efficient synthesis of a library of 2-amino-6-styryl pyrimidines (4) and their dihydro analogues (3) has been reported. Most of the saturated compounds (3) rather than their unsaturated analogues (4) showed better anti-bacterial (in vitro) activity against three human pathogens viz. Staphylococcus aureus, Klebsiella pneumonia and Escherichia coli. In particular, three of them (3 b, 3 i &3 k) exhibited high inhibition against the growth of all the three pathogens comparable with that of the reference drug, tetracycline.
Assuntos
Antibacterianos/síntese química , Antibacterianos/farmacologia , Escherichia coli/efeitos dos fármacos , Klebsiella pneumoniae/efeitos dos fármacos , Pirimidinas/química , Pirimidinas/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Água/química , Humanos , Técnicas In Vitro , Testes de Sensibilidade Microbiana , Estrutura Molecular , Relação Estrutura-AtividadeRESUMO
A rapid and efficient one pot solvent/scavenger-free protocol for the synthesis of 2-iminothiazolidin-4-ones has been developed. Interestingly, the regio/stereoselective synthesis affords the regioisomeric (Z)-3-alkyl/aryl-2-(2-phenylcyclohex-2-enylimino)thiazolidin-4-one as the sole product in good yield. The selectivities observed have been rationalized based on the relative magnitude of the allylic strains developed during the course of the reaction. This is the first report wherein the impact of allylic strains in directing the regiocyclization has been noted.
RESUMO
Efficient and rapid synthesis of 1,2,3-triazole derivatives has been achieved via Huisgen's 1,3-dipolar cycloaddition between alkyl/arylazides and diethyl/dimethyl acetylenedicarboxylate in excellent yields under solvent-free conditions. The environmentally friendly solvent-free protocol overcomes the limitations associated with the prevailing time-consuming solution phase protocols and affords the triazoles just in 1-3 min. In vitro antitubercular activity of these triazoles was screened against Mycobacterium tuberculosis H(37)Rv strain. Four of the compounds showed MIC in the range of 1.56-3.13 µg/mL proving their potential activity.
Assuntos
Antituberculosos/farmacologia , Mycobacterium tuberculosis/efeitos dos fármacos , Triazóis/farmacologia , Alcinos/química , Antituberculosos/síntese química , Antituberculosos/química , Azidas/química , Ácidos Graxos Insaturados/química , Testes de Sensibilidade Microbiana , Triazóis/síntese química , Triazóis/químicaRESUMO
A supramolecular approach to catalyzing the Ritter reaction by utilizing enhanced anion-binding affinity in the presence of alkali metal cations was developed with ditopic hydrogen-bonded amide macrocycles. With prebound cations in the macrocycle, particularly Li+ ion, their metal complexes exhibit greatly enhanced catalytic activities. The catalysis is switchable by removal or addition of the bound cation. The method described in this work may be generalized for use in other anion-triggered organic reactions involving heteroditopic receptors capable of ion pairing.