9, 24.3, 54.9–60.0 ppm for SCH3, CH3, and OCH3 respectively. The signals appeared at around δ 107.0, 114.0, 143.0, 162.0 ppm for C-5, C-6, C-7a, C-2 and carbons of aromatic rings at δ 127.0–134.0 ppm respectively. Further HRMS gave all the molecular ion peaks corresponding to molecular weight of confirmed novel compounds. In the present paper, we report the synthesis, spectral studies, and antifungal activity of a new series of novel diaryl substituted imidazo [2, 1-b]-benzothiazole derivatives (8a–y). These novel heterocyclic compounds were prepared by cyclo–dehydration
reaction between the various substituted 2-amino benzothiazole derivatives (3a–h) and various substituted a-bromo-1-[4′-substituted] phenyl-2-[4″-substituted] phenyl-1-ethanones (7a–i) in the presence of anhydrous ethanol, under the influence of a trace quantity Epacadostat solubility dmso of phosphorus pentoxide. In general, the results of the antifungal activity are also encouraging, as out of twenty five compounds tested, compounds 8k, 8l, 8m, 8n, 8q, 8r and 8y exhibited significant activities, which are comparable or more potent regarding their activity than the reference drug. The overall outcome of this model revealed that: (i) the imidazo [2, 1-b]-benzothiazole nucleus ring is satisfactory backbone for antifungal activity, (ii) presence of a nitro (-NO2), or carboxylic acid functional group at position C-6 and C-7 of the imidazo [2, 1-b]-benzothiazole
nucleus contributed to a better antifungal, (iii) presence of electron withdrawing group on the C-7 and phenyl ring at C-3 and of the imidazo [2, 1-b]-benzothiazole selleck screening library nucleus favors the activity. These preliminary encouraging results of biological screening of the tested compounds could offer an excellent framework in this field that may lead to discovery of potent
antifungal agent. 1H NMR spectra were measured at 300 MHz with a JEOL GSX 270 ft NMR spectrometer. from Chemical shifts were measured relative to internal standard TMS (δ: 0). 13C NMR spectra were recorded at 67.8 MHz on the same instrument with internal TMS (δ: 0, CDCl3). IR spectra were recorded on a UNICAM series FT-instrument. Mass spectra were recorded on AEI MS 902 or VG ZAB-E-instruments. Microanalyses were performed by MEDAC Ltd, Surrey. Melting points were determined on Gallenkamp capillary melting point apparatus and are uncorrected. Optical rotations were measured in chloroform solution using a Bellingham and Stanley ADP 220 polarimeter. Flash chromatography was performed using Fluka silica gel 60 (230–400 mesh). Thin layer chromatography was carried out using pre-coated aluminum plates (Merck Kieselghur 60 F254) which were visualized under UV light and then with either phosphomolybdic acid or basic aqueous potassium permanganate as appropriate. The appropriately substituted aniline (0.1 mol) and potassium thiocyanate (0.2 mol) were dissolved in 150 mL of glacial acetic acid, cooled in ice, and stirred mechanically while a solution of bromine (0.