1153-90-8Relevant academic research and scientific papers
Efficient and convenient synthesis, characterization, and antimicrobial evaluation of some new tetracyclic 1,4-benzothiazines
Mor, Satbir,Nagoria, Savita
, p. 169 - 178 (2016/02/23)
In the present study, 20 new tetracyclic 1,4-benzothiazines (4a-4 t) were conveniently synthesized in good yields and characterized by different spectral and physical techniques. The in vitro antimicrobial evaluation of the synthesized benzothiazine derivatives was performed by serial dilution against two Gram-positive bacteria [Bacillus subtilis (MTCC 441) and Staphylococcus epidermidis (MTCC 6880)], two Gram-negative bacteria [Escherichia coli (MTCC 1652) and Pseudomonas aeruginosa (MTCC 424)], and two fungal strains [Candida albicans (MTCC 227) and Aspergillus Niger (MTCC 8189)]. The derivatives 4 l and 4 t were found to be more potent than standard drug, i.e., fluconazole, against A. Niger and C. albicans, respectively.
Reactions of Carbonyl Compounds in Basic Solutions. Part 9. Methoxide-catalysed Cyclization of Benzylidenephthalides and Methyl o-Phenylacetylbenzoates
Bowden, Keith,Chehel-Amiran, Mohsen
, p. 2031 - 2034 (2007/10/02)
The detailed mechanism of the methoxide-catalysed rearrangement of substituted benzylidenephthalides and both normal and pseudo methyl o-phenylacetylbenzoates to form 2-phenylindane-1,3-diones has been studied.A rate-acidity function correlation for the reactions in methanolic dimethyl sulphoxide (DMSO) shows a linear increase in rate with increasing H- to reach a maximum in rate before decreasing, except for the p-nitro substrate.This derivative shows a rate decrease throughout the H- range.The ρ values in methanol and in 94 mol percent methanolic DMSO are 1.7 and -1.6, respectively.The kinetic isotope effect has been observed with kH/kD 0.8-1.0.The equilibrium constants for ring-chain tautomerism of the methyl o-phenylacetylbenzoates have been determined and shown to be independent of substituent and solvent composition.The rate-determining step is the intramolecular attack of the anion of the normal ester on the ester carbonyl group.In methanol and methanolic DMSO of high methanol content this is preceded by the ionization equilibrium of the normal ester.In methanolic DMSO of low methanol content and for the p-nitro substrate, the initial state is the anion itself.
