نتایج جستجو برای: oxazine
تعداد نتایج: 360 فیلتر نتایج به سال:
An approach to β-D-2-aminotalose- and β-D-2-aminoidose-configured carbohydrate mimetics bearing a phenyl substituent is described. Unnatural divalent rigid p-terphenyl-linked C-aryl glycosides with 2.0 nm dimension are available using Suzuki cross-couplings. The key compound, a p-bromophenyl-substituted 1,2-oxazine, was prepared by a stereoselective [3 + 3]-cyclization of a D-isoascorbic acid-d...
The title compound, C(34)H(24)Cl(4)N(4)O(8)S, is a linear penta-cyclic system formed of two substituted benzoxazinyl groups fused to 2-n-butyl-tetra-hydro-thio-phene. The oxazine ring, which is fused to the n-butyl-substituted side of the thio-phene ring, is in a boat conformation. The other fused oxazine ring and the tetra-hydro-thiene ring are each in an envelope conformation. The bridgehead ...
One of the most important goals in medicinal chemistry is the development of new techniques and new heterocyclic compounds with pharmaceutical activity. The present study aimed to use a method for the synthesis of some 1,2-Dihydro-1-arylnaphtho [1,2-e] [1,3] oxazine-3-ones. The question this study tried to answer was this reaction can be performed in present of nano-Fe2O3 as an acid catalyst an...
Ethenetricarboxylic acid diester 1a is a useful compound bearing two reactive sites, a CO2H group and a Michael acceptor. Reactions of 1a and reagents with oxygen and nitrogen nucleophilic moieties have been examined. The reaction of 1a with 2-aminoalcohols in the presence of EDCI and HOBt in one pot gave N,O-containing heterocyclic compounds, regioselectively. The stepwise method has also been...
A new set of photochromic hindered benzo- and naphtho[1,3]oxazines with fast switching speed between the closed and open form were synthesised. Laser excitation of these uncoloured molecules (with ∼10 ns FWHM pulses) leads to the cleavage of the C-O bond and opening of the oxazine ring in less than 20 ns, generating a thermally unstable coloured zwitterionic species that reverts in few nanoseco...
The electrogenerated chemiluminescence (e.c.!.) and electrochemistry of the laser dyes, coumarin-2, coumarin-3D, rhodamine-GG (perchlorate), rhodamine-B (perchlorate), oxazine1 (perchlorate), and Nile Blue (perchlorate) were studied in acetonitrile using 0.1 M tetran-butylammonium perchlorate (TBAP) as a supporting electrolyte. Rather low intensity e.c.!. was obtained for all dyes except Nile B...
Peniciadametizine A (1); a new dithiodiketopiperazine derivative possessing a unique spiro[furan-2,7'-pyrazino[1,2-b][1,2]oxazine] skeleton, together with a highly oxygenated new analogue, peniciadametizine B (2); as well as two known compounds, brasiliamide A (3); and viridicatumtoxin (4), were isolated and identified from Penicillium adametzioides AS-53, a fungus obtained from an unidentified...
In the title compound, C23H19NO2, an oxazine Mannich base derivative, the oxazine ring has a half-chair conformation. The 2-hy-droxy-naphthalen-1-yl substituent is placed in an axial position. There is an intra-molecular O-H⋯N hydrogen bond, forming an S(6) graph-set motif. In the crystal, mol-ecules are connected by a pair of C-H⋯π inter-actions into an inversion dimer, which is reinforced by ...
Forecasting of aperiodic time series is a compelling challenge for science. In this work, we analyze aperiodic spectrophotometric data, proportional to the concentrations of two forms of a thermoreversible photochromic spiro-oxazine, that are generated when a cuvette containing a solution of the spiro-oxazine undergoes photoreaction and convection due to localized ultraviolet illumination. We c...
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