Lidiya A. Petrushova

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A new, effective preparative method has been proposed and the synthesis of a series of N-(arylalkyl)-1-R-4-hydroxy-2,2-dioxo-1H-2λ(6),1-benzothiazine-3-car-boxamides has been carried out. It has been shown that amidation of alkyl 1-R-4-hydroxy-2,2-dioxo-1H-2λ(6),1-benzothiazine-3-carboxylates with arylalkyl-amines in boiling xylene proceeds with good yield(More)
The fact that molecular crystals exist as different polymorphic modifications and the identification of as many polymorphs as possible are important considerations for the pharmaceutic industry. The molecule of N-benzyl-4-hydroxy-1-methyl-2,2-dioxo-1H-2λ(6),1-benzothiazine-3-carboxamide, C17H16N2O4S, does not contain a stereogenic atom, but intramolecular(More)
An x-ray crystal structure analysis found that the bromination of methyl 1-allyl-4-hydroxy-2,2-dioxo-1H-2λ6,1-benzothiazine-3-carboxylate by Br2 in glacial HOAc involved not heterocyclization but classical addition of Br2 to the unsaturated allyl bond, in contrast with structurally similar alkyl 1-allyl-4-hydroxy-2-oxo-1,2-dihydroquinoline-3-carboxylates.(More)
In continuing the search for new analgesics among derivatives of 2,1-benzothiazines, a series of corresponding toluidides and xylidides of 4-hydroxy-2,2-dioxo-1H-2λ⁶,1-benzothiazine-3-carboxylic acid has been synthesized by the reaction of ethyl 4-hydroxy-2,2-dioxo-1H-2λ⁶,1-benzothiazine-3-carboxylate with equimolar amounts of mono- and dimethyl-substituted(More)
In order to obtain and then test pharmocologically any possible conformers of the new feasible analgesic N-benzyl-4-hydroxy-1-methyl-2,2-dioxo-1H-2λ⁶,1-benzothiazine-3-carboxamide, its 4-O-sodium salt was synthesized using two methods. X-ray diffraction study made possible to determine that, depending on the chosen synthesis conditions, the above-mentioned(More)
As potential new analgesics, the corresponding 4-hydroxy-2,2-dioxo-1H-2λ⁶,1-benzothiazine-3-carboxanilides have been obtained by amidation of ethyl 4-hydroxy-2,2-dioxo-1H-2λ⁶,1-benzothiazine-3-carboxylate with aniline and its halogenated analogsin boiling dry xylene. The peculiarities of the mass and nuclear magnetic resonance (¹Н and 13С) spectra of the(More)
There are two independent mol-ecules in the asymmetric unit of the title compound, C13H13NO5S, in both of which the ester substituent is nearly coplanar [C-C-C-O torsion angles = 2.7 (7) and -0.8 (7)°] with the planar fragment of the bicycle due to the formation of a strong O-H⋯O intra-molecular hydrogen bond. The vinyl group at the ring N atom is(More)
Methyl-4-hydroxy-1-phenyl-2,2-dioxo-1H-2λ6,1-benzothiazine-3-carboxylate was found to undergo transesterification even during crystallization from EtOH to convert into the corresponding ethyl ester. The molecular structure of the obtained compound was studied. In particular, PMR spectroscopy and x-ray crystal structure analysis established that the(More)
The title solvate, C20H14N4O4S·C3H7NO, comprises a stereogenic centre but the centrosymmetric space group causes the presence of the racemate in the crystal. The spiro-joined fragments are almost orthogonal, with a dihedral angle of 86.8 (2)° between the mean planes of the pyrane ring and the dihydroindolone ring system. The atoms of the indolinone bicycle(More)