- Reaction of stable trialkylsilyl esters with Ph3P(SCN)2: A novel method for the preparation of acyl and aroyl isothiocyanates under neutral condition
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An efficient, mild and novel method is described for one-pot conversion of stable triisopropylsilyl- and tert-butyldimethylsilyl carboxylates to their corresponding acyl- or aroyl isothiocyanates using in-situ generation of Ph3P(SCN)2 at room temperature under neutral condition. This method has also been applied for the high yield preparation of 2-thioxo-3,4-dihydro-2H-1,3-benzoxazine-4-one, which has fungicidal and bactericidal activities.
- Iranpoor,Firouzabadi,Shaterian
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- Synthesis, DNA-PK inhibition, anti-platelet activity studies of 2-(N-substituted-3-aminopyridine)-substituted-1,3-benzoxazines and DNA-PK and PI3K inhibition, homology modelling studies of 2-morpholino-(7,8-di and 8-substituted)-1,3-benzoxazines
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A number of new 2-(pyridin-3-ylamino)-4H-(substituted) benz[e]-1,3-oxazin- 4-ones were synthesized 10a-g. These were then reacted with the hydro-halogen salt of 2, 3 and 4-(halo-methyl) pyridine in the presence of Cs 2CO3 to give eighteen new 2-(N-substituted (pyridin-3-ylmethyl) amino)-substituted-1,3-benzoxazines (compounds 11a-i, 13a-c, and 15a-f). X-ray crystallography was used to confirm that the 2-N-substituted structures 11 and 13 were formed rather than the 3-N-substitution analogues 12 and 14. Eleven of the new compounds were tested for their effect on collagen induced platelet aggregation and it was found that the most active inhibitory compound was 8-methyl-2-(pyridin-3-yl(pyridin-3- ylmethyl)amino)-7-(pyridin-3-ylmethoxy)-4H-benz[e]-1,3-oxazin-4-one 15e with an IC50 of 10 ± 2 μM. DNA-dependent protein kinase (DNA-PK) inhibition data for 12 previously prepared 2-morpholino substituted-1,3- benzoxazines (compounds 19-31) were measured and showed high to moderate activity where the most active compound was compound 27 with an IC50 of 0.28 μM. Furthermore DNA-PK inhibition data for six newly prepared 2-(N-substituted (pyridin-3-ylmethyl) amino)-substituted-1,3-benzoxazines (compounds 11b, 13a-b, 15a-b and 15e) and 8-methyl-7-(pyridin-3-ylmethoxy)-3- (pyridin-3-ylmethyl)-2H-benz[e]-1,3-oxazin-2,4(3H)-dione 17d were measured and moderate to low inhibitory activity was observed, with the most active of the compounds in this series being 8-methyl-2-(pyridin-3-yl(pyridin-3-ylmethyl) amino)-7-(pyridin-3-ylmethoxy)-4H-benz[e]-1,3-oxazin-4-one 15e with an IC 50 of 2.5 μM. PI3K inhibition studies revealed that compound 27 is highly potent (IC50 for PI3Kα = 0.13 μM, PI3Kβ = 0.14 μM, PI3Kγ = 0.72 μM, PI3Kδ = 2.02 μM). Compound 22 with 7-[2-(4-methylpiperazin-1-yl)ethoxy] group shows greater inhibition of DNA-PK over PI3K. Docking of some 2-morpholino-substituted-1,3-benzoxazine compounds 19-31 within the binding pocket and structure-activity relationships (SAR) analyses were performed with results agreeing well with observed activities.
- Ihmaid, Saleh K.,Al-Rawi, Jasim M.A.,Bradley, Christopher J.,Angove, Michael J.,Robertson, Murray N.
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- Generalized method for the production of 1,3-benzoxazine, 1,3-benzothiazine, and quinazoline derivatives from 2-(hydroxy, thio, or amino) aromatic acids using triphenylphosphine thiocyanogen
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A modified one-pot method was developed for the synthesis of 1,3-benzoxazines, in which the preparation of unstable thiocyanogen was omitted. The method was found to be general for substituted (methyl, methoxy, halo, and hydroxy) 2-hydroxy benzoic acids and 2-hydroxy naphthoic acids. The method was extended to 2-thio, 2-amino, and N-methyl aminobenzoic acid with which the synthesis of 1,3-benzothiazine and quinazoline derivatives has been achieved, respectively. It was also found that 3-hydroxypyridine-2-carboxylic acid and 2-hydroxynicotinic acid using a modified method gave 2-thioxo-2,3-dihydro-4H- pyrido[2,3-e][1,3]oxazin-4-one and 2-thioxo-2,3-dihydro-4H-pyrido[3,2-e][1,3] oxazin-4-one, respectively. The structures of the new compounds were confirmed by the analysis of their IR, 1H, and 13C NMR spectra. Copyright Taylor & Francis, Inc.
- Pritchard, Kaylene M.,Al-Rawi, Jasim M.,Hughes, Andrew B.
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p. 1601 - 1611
(2007/10/03)
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