نتایج جستجو برای: oxazine
تعداد نتایج: 360 فیلتر نتایج به سال:
An Inverse Decibel Log Frequency Method for Determination of the Transfer Functions of Psychobiological Systems: George L. Kreezer 681 Some New Finds of Fossil Ganoids in the Virginia Triassic: Francis M. Baer and William H. Martin .... 684 Colehicine Poisoning in Relation to Hemerocallis and Some Other Plants: Hamilton P.Traub ..................................................... 686 Preparati...
In the title compound, C(13)H(15)NO(2), the hexa-hydro-pyrrolo-[2,1-c][1,4]oxazine fragment is disordered over two conformations (A and B) in a 0.656 (5):0.344 (5) ratio. The five-membered ring is similarly disordered and adopts an envelope conformation in A, while in B this ring is nearly planar [maximum deviation = 0.088 (1) Å]. The six-membered rings in both A and B exhibit chair conformatio...
In this Letter, we investigated the dimerization behavior of the red-absorbing oxazine derivative MR121. Thereby a new method to determine absorption spectra of pure non-fluorescent H-type dye dimers is presented. Therefore, the amino acid lysine is doubly labeled with the fluorescent dye in order to obtain an absorption spectrum mainly caused by dimers. By subtracting the fraction arising from...
all-endo-3-amino-5-hydroxybicyclo[2.2.2]octane-2-carboxylic acid (13) and all-endo-5-amino-6-(hydroxymethyl)bicyclo[2.2.2]octan-2-ol (10) were prepared via dihydro-1,3-oxazine or g-lactone intermediates by the stereoselective functionalization of an N-protected derivative of endo-3-aminobicyclo[2.2.2]oct-5-ene-2-carboxylic acid (2). Ring closure of b-amino ester 4 resulted in tricyclic pyrimidi...
The oxazine ring in the title compound, C(21)H(14)N(2)O(5), adopts a flattened boat conformation. The nitro-phenyl ring and the naphthalene ring system enclose a dihedral angle of 89.2 (1)°. An intra-molecular hydrogen bond is formed between the NH group and one of the adjacent carbonyl O atoms. In addition, the NH group forms an inter-molecular hydrogen bond to a symmetry equivalent of this ca...
Nucleophilic substitution reactions of 2-halo-2H-azirines 1a, 1b, 1d, and 1e with potassium phthalimide and aniline allowed the preparation of new substituted 2H-azirines 2-5. The reactions of 2-bromo-2H-azirine 1a with methylamine led to the synthesis of alpha-diimines 7 and 8. 2-Halo-2H-azirines were also established as building blocks for the synthesis of a range of heterocyclic compounds, n...
In the title compound, C(11)H(10)N(2)O(2), a potential inhibitor of the cyclo-oxygenase-2 isoenzyme, the pyrazoline ring exists in a flat-envelope conformation while the puckering of the central oxazine ring is more severe. As a result, the mol-ecule as a whole is non-planar. The formal sp(3) pyrazoline N atom is sp(2) hybridized, with the lone-pair electrons delocalized through conjugation wit...
The regioselective conversion of propargylic alcohols into previously unreported α,α-diiodo-β-hydroxyketones was achieved by treatment with N-iodosuccinimide in the presence of a gold catalyst. The corresponding α,α-dichloro-β-hydroxyketones were obtained by treatment with trichloroisocyanuric acid in the absence of a catalyst. The latter reaction can be extended to other alkynols. These transf...
In the title compound, C(19)H(17)ClN(2)O(2), the pyrazole ring is almost planar with a maximum deviation of 0.009 (3) Å and makes a dihedral angle of 8.96 (9)° with the oxazine ring. The dihedral angles between the pyrazole ring and the chlorine- and meth-oxy-substituted benzene rings are 50.95 (8) and 13.24 (9)°, respectively. An inter-molecular C-H⋯N hydrogen bond links the mol-ecules into in...
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