Structure determination of some 5,6-dihydropyrrolo-[1,2-a][3,1,6]benzothiadiazocines

The conformation of compounds 1 and 2 has been determined in the solid state by X-ray crystallography and in solution by nmr spectroscopy. MM2 and molecular dynamics calculations were used to determine the conformation of compound 2 in vacuo and in solution.     

Polycondensed nitrogen heterocycles. IX. 5,6-dihydro-7H-pyrrolo[1,2-d][1,4]benzodiazepin-6-one

The reaction of amino derivative I with bromoacetyl bromide led to the formation of a complex mixture from which, in addition to the title compound, which was formed in low yield, compounds III, IV and VI were separated. Pyrrolo[1,2-d][1,4]benzodiazepine V was obtained in 85% yield when the bromoamide III was treated with an equimolar amount of potassium t-butoxide.     

Benzoxadiazocines,benzothiadiazocines and benzotriazocines-V : The synthesis of some 2-amino-6-methyl- and 2-amino-6-phenyl-5,6-dihydro-4h-3,1,6-benzothiadiazocines

A method is described for the synthesis of hydrochlorides of some type 8 title compounds in which the nucleophilicity of N-2 is reduced or completely lost so as to prevent ring contraction reactions and, as a result, making these compounds comparatively stable.     

Synthesis of 3-methyl-7-phenylimidazo-[1,2-b]-1,2,4-triazine

The bromocyclization of 3-allylamino-5-phenyl-1,2,4-triazine gives 3-bromomethyl-7-phenyl-2,3-dibromo-1H-imidazo[1,2-b]-1,2,4-triazinium bromide, which is transformed into 3-methyl-7-phenylimidazo-[1,2-b]-1,2,4-triazine.Yekaterinburg Fire-Fighting Technical Institute, Ministry of Internal Affairs, Russian Federation, 620002 Yekaterinburg. Chelyabinsk State University, 454136 Chelyabinsk. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 110–111, January, 1998.     

Synthesis of 3-benzoyl-4,7-dihydro-7-oxopyrrolo[3,2-b]pyridine-6-carboxylic acid derivatives as potential antimicrobial agents

A series of twelve newly synthesized derivations of 3-benzoyl-4,7-dihydro-7-oxopyrrolo[3,2-b]pyridine-6-carboxylic acid from 2-methyl-3-benzoyl-4-aminopyrrole is reported.     

Synthesis of 5,6-dihydro-4H-pyrrolo[1,2-a]thieno[2,3-f][1,4]diazepines

The reduction of 1-[3-(thienyl-2-carbonitrile)]pyrrole, formed by condensation of 3-aminothiophene-2-carbonitrile with 2,5-dimethoxytetrahydrofuran, gave 1-[3-(thienyl-2-aminomethyl)]pyrrole. This compound was found to be a convenient intermediate for the preparation of 4-aryl-5,6-dihydro-4H-pyrrolo[1,2-a]thieno-[2,3-f][1,4]diazepines which was accomplished by two different synthetic routes.     

First synthesis of 5,6-dihydro-4H-furo[3,2-f]pyrrolo- [1,2-a][1,4]diazepines

The synthetic pathway leading to 5,6-dihydro-4H-furo[3,2-f]pyrrolo[1,2-a][1,4]diazepines is described in four steps starting from α-bromophenones via 2-amino-3-furonitriles.     

Synthesis of 8-cyano-1,4-dihydro-4-oxopyrrolo[1,2-a]pyrimidine-3-carboxylic acids as potential antimicrobial agents

The preparation of a variety of 8-cyano-1,4-dihydro-7-phenyl-4-oxopyrrolo[1,2-a]pyrimidine-3-carboxylicacids and 8-cyano-1,4-dihydro-7-p-fluorophenyl-4-oxopyrrolo[1,2-a]pyrimidine-3-carboxylic acids is described.     

Crystal structure of 6,11-dihydro-6,11-methano-5H-benzo[5,6]cyclohepta[1,2-b]pyridinol-11

X-ray structure of 6,11-dihydro-6,11-methano-5H-benzo[5,6]cyclohepta[1,2-b]pyridinol-11 is determined.     

2-R-5-Ar(Het)-5,6-dihydro-7H-[1,2,4]triazolo[5,1-b][1,3]thiazin-7-ones

A novel method for synthesis of 2-R-5-Ar(Het)-5,6-dihydro-7H-[1,2,4]triazolo[5,1-b][1,3]thiazin-7-ones by condensation of 3-R-4,5-dihydro-1H-1,2,4-triazole-5-thiones with 3-aryl(heteryl)-2-propenoyl chlorides is proposed.     

Synthesis and Crystal Structure of 7-Ethoxycarbonyl-2-methyl-6-methylthio-lH-imidazo[1,2-b]pyrazole

The title compound 7-ethoxycarbonyl-2-methyl-6-methylthio-1H-imidazo[1,2-b]-pyrazole (Mr = 239.29) was synthesized and structurally characterized by IR, 1H NMR and single-crystal X-ray diffraction. It belongs to the triclinic system, space group P1, with a = 8.0461(10), b = 8.5534(11), c = 9.5605(12) A, α = 64.804(2), β = 74.231(2), γ = 76.885(2)°, V= 568.27(12) A3, Z = 2, Dc = 1.398 g/cm3,μ= 0.274 mm-1, F(000) = 252, the final R.= 0.0454 and wR = 0.1261. A total of 3360 reflections were collected, of which 2466 were independent (Rint = 0.0138) and 2154 were observed with I > 2σ(Ⅰ).     

The synthesis of 7,8-dihydroimidazo[1,2-e]pyrazolo[1,5-a]-1,3,5-triazines, 8,9-dihydro-7H-pyrimido[1,2-e]pyrazolo[1,5-a]-1,3,5-triazines and 7,8,9,10-tetrahydro[1,3]diazepino[1,2-e]pyrazolo[1,5-a]triazines

Cyclic hydrazino amidines were converted to the corresponding aminopyrazolyl derivatives. Ring closure between the amino groups of pyrazoline moieties and NH groups of cyclic amidines afforded the following ring systems: 7,8-Dihydroimidazo[1,2-e]pyrazolo[1,5-a]-1,3,5-triazines, 8,9-dihydro-7H-pyrimido[1,2-e]pyrazolo[1,5-a]-1,3,5-triazines and 7,8,9,10-tetrahydro[1,3]diazepino[1,2-e]pyrazolo[1,5-a]-1,3,5-triazines.     

Synthesis of novel 3-carboethoxy-6-methyl-4-oxo-4H-pyrimido[1′,2′:5,6]-[1,3,5]triazino[1,2-a]benzimidazoles

Reaction of 4-amino-2-methylbenzimidazo[1,2-a][1,3,5]triazines 2 with diethyl ethoxymethylenemalonate afforded 3-carboethoxy-6-methyl-4-oxo-4H-pyrimido[1′,2′:5,6][1,3,5]triazino[1,2-a]benzimidazoles 3 , a new ring system.     

Synthesis of 1,4-dihydro-4-oxopyrrolo[1,2-b]pyridazine-3-carboxylic acids and 1,4-dihydro-4-oxoimidazo[1,5-b]pyridazine-3-carboxylic acids as potential antibacterial agents

To check the antibacterial potential of two families of aza analogues of the quinolones, 1,4-dihydro-4-oxopyrrolo[1,2-b]pyridazine-3-carboxylic acids and 1,4-dihydro-4-oxoimidazo[1,5-b]pyridazine-3-carboxylic acids, we have prepared a few derivatives in theses families using N-aminopyrrole and N-aminoimidazole derivatives as starting building blocks and the classical pathways of the quinolone series. The compounds showed no interesting antibacterial activity.     

Cyclocondensation of 6-acetyl-4,7-dihydro-5-methyl-7-phenyl[1,2,4]triazolo[1,5-a]pyrimidine with hydroxylamine and hydrazine

The cyclocondensation of 6-acetyl-4,7-dihydro-5-methyl-7-phenyl[1,2,4]triazolo[1,5-a]pyrimidine (3) with hydroxylamine or hydrazine leads to 3a,4,9,9a-tetrahydro-3,9a-dimethyl-4-phenylisoxazolo-[5,4-d][1,2,4]triazolo[1,5-a]pyrimidine ( 4a ) and 3a,4,9,9a-tetrahydro-3,9a-dimethyl-4-phenyl-1H-pyrazolo[3,4-d][1,2,4]triazolo[1,5-a]pyrimidine ( 4b ), respectively. In the presence of methanolic hydrogen chloride, 4b undergoes a cleavage of the pyrimidine ring to yield (5-amino-1,2,4-triazol-1-yl)(3,5-dimethylpyrazol-4-yl)phenylmethane ( 5 ). The structure determination of the compounds obtained is based on ¹H and ¹³C nmr spectra including NOE measurements.