Synthesis of 1-methyl-7-(trifluoromethyl)-1H-pyrido[2,3-c][1,2]thiazin-4(3H)-one 2,2-dioxide

The reaction of methyl 2-bromo-6-(trifluoromethyl)-3-pyridinecarboxylate ( 1 ) with methanesulfonamide gave methyl 2-[(methylsulfonyl)amino]-6-(trifluoromethyl)-3-pyridine-carboxylate ( 2 ). Alkylation of compound 2 with methyl iodide followed by cyclization of the resulting methyl 2-[methyl(methylsulfonyl)amino]-6-(trifluoromethyl)-3-pyridinecarboxylate ( 3 ) yielded 1-methyl-7-(trifluoromethyl)-1H-pyrido[2,3-c][1,2]thiazin-4(3H)-one 2,2-dioxide ( 4 ). The reaction of compound 4 with α,2,4-trichlorotoluene, methyl bromopropionate, methyl iodide, 3-trifluoromethylphenyl isocyanate, phenyl isocyanate and 2,4-dichloro-5-(2-propynyloxy)phenyl isothiocyanate gave, respectively, 4-[(2,4-dichlorophenyl)methoxy]-1-methyl-7-(trifluoromethyl)-1H-pyrido[2,3-c][1,2]thiazine 2,2-dioxide ( 5 ), methyl 2-[[1-methyl-2,2-dioxido-7-(trifluoromethyl)-1H-pyrido[2,3-c][1,2]thiazin-4-yl]oxy]propanoate ( 6 ), 1,3,3-trimethyl-7-(trifluoromethyl)-1H-pyrido[2,3-c][1,2]thiazin-4(3H)-one 2,2-dioxide ( 7 ), 4-hydroxy-1-methyl-7-(trifluoromethyl)-N-[3-(trifluoromethyl)phenyl]-1H-pyrido[2,3-c][1,2]thiazine-3-carboxamide 2,2-dioxide ( 8 ), 4-hydroxy-1-methyl-7-(trifluoromethyl)-N-phenyl-1H-pyrido[2,3-c][1,2]thiazine-3-carboxamide 2,2-dioxide ( 9 ) and N-[2,4-dichloro-5-(2-propynyloxy)phenyl]-4-hydroxy-1-methyl-7-(trifluoromethyl)-1H-pyrido[2,3-c][1,2] thiazine-3-carboxamide 2,2-dioxide ( 10 ).     

Condensation of 6-methyl-3-azapyrylium salts to pyrido[1,2-c]pyrimidinium derivatives

Under the influence of DMF/Ac₂O 2,4-diphenyl-6-methyl-3-azapyrylium perchlorates undergo condensation to give pyrido[1,2-c]pyrimidinium perchlorates. The structure of one of the perchlorates was proved by x-ray diffraction analysis.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1556–1561, November, 1991.     

由N-苯基[1,3]苯并噁嗪正离子与烯烃[4+2]反应合成喹啉并[1,2-c][1,3]苯并噁嗪-6-酮衍生物

以BF3·OEt2 为催化剂, 在室温下通过4-羟基-N-苯基[1,3]苯并噁嗪-2-酮的脱羟基产生N-苯基[1,3]苯并噁嗪正离子, 然后与富电子烯烃发生Diels-Alder反应, 合成出了一系列喹啉并[1,2-c][1,3]苯并噁嗪-6-酮和喹啉并[1,2-c][1,3]萘并噁嗪-6-酮衍生物.     

Synthesis of novel imidazo[1,2-a][3,1]benzothiazines 4, imidazo[1,2-a]-[1,2,4]benzotriazines 5, and 4H-imidazo[2,3-c]pyrido[2,3-e][1,4]oxazines 6

Starting from the readily available 2-aminobenzhydrols ( 7 ), 3-amino-1,2,4-benzotriazine ( 11 ) and 2-amino-3-pyridinol ( 12 ), novel derivatives of 5-phenyl-5H-imidazo[1,2-a][3,1]benzothiazine-2-carboxylic acid, ethyl ester ( 4 ), imidazo[2,1-c][1,2,4]benzotriazine-2-carboxylic acid, ethyl ester ( 5 ) and 4H-imidazo[2,3-c]pyrido-[2,3-e][1,4]oxazine ( 6 ) were prepared.     

Synthesis of 2-Alkyl（aryl）-3-methylthio-6-methyl-6-arylpyrano-[4, 3-c]pyrazol-4（2H）-ones

The synthesis of 2-alkyl(aryl)-3-methylthiopyrano[4,3-c]pyrazol-4(2H)-ones via 5, 6-dihydro-2H-pyran-2, 4-dione-3-dithioacetals with (un)substituted hydrazines is described and the mechanism of the formation of title compounds is discussed. Their structures were confirmed by ^1HNMR spectra and elemental analysis.     

Synthesis and spectral analysis of (±)-cis-N-[1-(2-hydroxy-2-phenyl-ethyl)-3-methyl-4-piperidyl]-N-phenylpropanamide and (±)-cis-N-[1-(2-hydroxy-1-phenylethyl)-3-methyl-4-piperidyl]-N-phenylpropanamide

Treatment of (±)-cis-N-(3-methyl-4-piperidyl)-N-phenylpropanamide (2) with styrene oxide (1) yielded a mixture of (±)-cis-N-[1-(2-hydroxy-2-phenylethyl)-3-methyl-4-piperidyl]-N-phenylpropanamide (3) and (±)-cis-N-[1-(2-hydroxy-1-phenylethyl)-3-methyl-4-piperidyl]-N-phenylpropanamide (4) . The structure of compound 3 was confirmed by an unambiguous synthesis via (±)-cis-N-[1-(2-oxo-2-phenylethyl)-3-methyl-4-piperidyl]-N-phenylpropanamide (6) . The proton and carbon-13 resonances of compounds 3 and 4 were assigned with the aid of two-dimensional heteronuclear correlation experiments.     

Synthesis of pyrido[1,2-b][2,4]benzodiazepin-6(11H)-imines

Condensation of o-bromomethylbenzonitrile and -bromo-o-cyanophenylmethane with 2-aminopyridines gives 6-amino-6,11-dihydropyrido[1,2-b][2,4]benzodiazepines. Quaternary 2-aminopyridinium salts are intermediates in these reactions.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1264–1269, September, 1987.     

Synthesis and Biological Activity of Pyrazolo[1,5-c][1,3]benzoxazines Containing a Thiazolidin-4-one Fragment

Russian Journal of Organic Chemistry - 5-[4-(2-Aryl-1,10b-dihydropyrazolo[1,5-c][1,3]benzoxazin-5-yl)benzylidene]-1,3-thiazolidin-4-ones were synthesized by reactions of...     

Synthesis of new pyrido[3,2-b][1,4]benzoxazines and -benzothiazines

Russian Chemical Bulletin - New pyrido[3,2-b][1,4]benzoxazines and pyrido[3,2-b][1,4]benzothiazines were synthesized by the base-mediated reactions of substituted 2-chloro-3-nitropyridines with...     

Synthesis of 5-Alkyl-1,3-bis[2-hydroxy-3-(6-methyl-2,4-dioxo-1,2,3,4-tetrahydropyrimidin-3-yl)propyl]-6-methyl-1,2,3,4-tetrahydropyrimidine-2,4-diones

6-Methyluracil sodium salt reacts with 1,3-bis(3-chloro-2-hydroxypropyl)-6-methyluracils in DMF, yielding products of alkylation at the nitrogen atom in position 3 of the uracil ring.     

Synthesis and molecular structure of 3,7-dimethyl-2-[N-(4-methylpyridyl-2)-4-hydroxy-3-methyl-5-oxopyrrolen-3-yl-2]imidazo[1,2-a]pyridine

Heterocyclization of 2-chloroepoxy-1,1-diethoxy-2.3-butane with 2-amino-4-methylpyridine occurred with participation of all three potential electrophilic centers to give 3,7-dimethyl-2-[N-(4-methylpyridyl-2)-4-hydroxy-3-methyl-5-oxopyrrolen-3-yl]imidazo[1,2-a]pyridine, the structure of which was determined by X-ray crystallography. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, 1089–1094, July 2006.     

Synthesis of 3-tert-Butyl-4-hydroxy-1,4-dihydropyrazolo[5,1-c][1,2,4]triazines

Russian Journal of Organic Chemistry - Two new approaches have been proposed for the synthesis of 4-hydroxy-1,4-dihydropyrazolo[5,1-c]-[1,2,4]triazines via (1) borohydride reduction of...     

Synthesis of phosphodiesterase IVb inhibitors 2. Stereoselective synthesis of hexahydro-3H-pyrrolo[1,2-c]imidazol-3-one and tetrahydro-1H-pyrrolo[1,2-c][1,3]oxazol-3-one derivatives

The total stereoselective synthesis of two highly potent phosphodiesterase IVb inhibitors from nitroethane, isovanillin, and ethyl vinyl ether was developed. The compounds obtained are the derivatives of hexahydro-3H-pyrrolo[1,2-c]imidazol-3-one and tetrahydro-1H-pyrrolo[1,2-c][1,3]oxazol-3-one. The strategy proposed involves silylation of six-membered cyclic nitronates as a key step leading to 5,6-dihydro-4H-1,2-oxazines with the group CH₂FG (FG = N₃ or OH) at the C(3) atom.     

Synthesis and Crystal Structure of 1-Ethyl 3-Methyl 6-Benzyl-2-methyl-5-oxo-5,6-dihydropyrrolo[1,2-c]quinazoline-1,3-dicarboxylate

The crystal structure of the title compound(C24H22N2O5, Mr = 418.44) has been determined by single-crystal X-ray diffraction. The crystal is of orthorhombic, space group P21/c with a = 7.751(2), b = 12.392(4), c = 21.326(6), V = 2048.4(1)3, Z = 4, Dc = 1.357 g/cm3, F(000) = 880, μ(MoKα) = 0.096 mm-1, the final R = 0.0731 and wR = 0.1982 for 3335 observed reflections(I 2σ(I)). Intermolecular C(24)–H(24B)···O(1) hydrogen bond is observed in the structure.