Synthesis and spectral properties of substituted [1,2,4]oxadiazolo[4,5-a] [1,5] benzodiazepines

The preparation of twelve novel substituted [1,2,4]oxadiazolo[4,5-a][1,5]benzodiazepines which have potentially useful pharmacological properties; by 1.3-dipolar cycloaddition of benzonitrile oxides, generated in situ from benzohydroxamoyl chloride and triethylamine, to 1,5-benzodiazepine derivatives, is described. The structure of all products was corroborated by ir, ¹H-nmr, ¹³C-nmr and ms.     

Synthesis of (7-Aryl-5-methyl-4,7-dihydrotetrazolo[1,5-a]pyrimidin-6-yl)(phenyl)methanones

Russian Journal of Organic Chemistry - (7-Aryl-5-methyl-4,7-dihydrotetrazolo[1,5-a]pyrimidin-6-yl)(phenyl)methanones were synthesized by three-component condensation of 1-phenylbutane-1,3-dione...     

Synthesis and stereochemistry of novel [1,2,4]oxadiazolo[4,5-a][1,5]benzodiazepine derivatives

An one-pot synthetic approach to the novel 3a,4,5,6-tetrahydro[1,2,4]oxadiazolo[4,5-a][1,5]benzodiazepine system, by 1,3-dipolar cycloaddition of benzonitriloxides to 1,5-benzodiazepine derivatives, is described. The structure and stereochemistry of the obtained adducts have been assigned by means of spectroscopic measurements.     

Synthesis,Structure, and Antibacterial Activity of Alkyl 6-Aroyl-7-aryl-4,7-dihydrotetrazolo[1,5-a]pyrimidine-5-carboxylates

Russian Journal of General Chemistry - A series of new alkyl 6-aroyl-7-aryl-4,7-dihydrotetrazolo[1,5-a]pyrimidine-5-carboxylates was obtained through the three-component reaction of alkyl esters...     

Synthesis of N,N-dimethyl(diethyl)-7-aryl-5-methyl-4,7-dihydrotetrazolo[1,5-a]pyrimidine-6-carboxamides

Russian Journal of Organic Chemistry -     

Synthesis of new substituted pyrazolo[1,5-a]-pyrimidines and pyrazolo[1,5-a]1,3,5-triazines

5-Substituted 3-amino-1H-pyrazole-4-carbonitriles 2a-d react with appropriate biselectrophilic reagents in the presence of (TEA) to give the substitution products pyrazolo[1,5-a]pyrimidines 4a-d, 6a-d and pyrazolo[1,5-a ]1,3,5-triazines 8a-d. Compounds 6a and 8a react with secondary amines to 10a-c and 11a-c. Treatment of 2a with malonodinitrile results in the substituted pyrazolo-[1,5-a]pyrimidine 16. Condensation of 2a, 2c and 2d with ethyli-dene-malodintriles leads to racemic dihydro-pyrazolo[1,5-a] pyr-imidines 18a-e. Reaction of diene 20 with the heterodienophile 21 leads to formation of Diels-Alder adduct 22.     

Indazolo[2,3-a] quinazoline

Zinc-acetic acid reduction of 2,2′-dicyanoazobenzene affords, beside the expected 5-amino-indazolo[2,3-a]quinazoline, the previously unreported parent compound: indazolo[2,3-a]quin-azoline.     

Iodine-Catalyzed,Multicomponent, One-Pot Synthesis of 5-Aryl-5,8-dihydrotetrazolo[1,5-a]pyrimidine-7-carboxylic Acids

A series of 5-aryl-5,8-dihydrotetrazolo[1,5-a]pyrimidine-7-carboxylic acids (4) were synthesized from 5-aminotetrazole, pyruvic acid, and aromatic aldehydes in one pot in the presence of I₂ with moderate to good yields. Operational simplicity, mild reaction conditions, and ecofriendly procedure make this novel protocol a promising alternative for the fusion of tetrazolopyrimidines. The structures of the products were proved by ¹H and ¹³C NMR spectroscopy, liquid chromatography–mass spectrometry, and elemental analysis.      

Synthesis of 4-alkylpyrazolo[1,5-a]benzimidazoles

2,4-Disubstituted pyrazole[1,5-a]benzimidazoles were obtained by the action of carboxylic acid anhydrides on 1-amino-2-methyl-3-alkylbenzimidazolium salts in the presence of potassium carbonate. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 814–817, June, 1980.     

Facile Regioselective On-Water Synthesis of 4,7-Dihydropyrazolo[1,5-a]Pyrimidines and 4,7-Dihydro[1,2,4]Triazolo[1,5-a]Pyrimidines

Chemistry of Heterocyclic Compounds - Efficient and regioselective on-water synthesis of variously substituted 5-amino-4,7-dihydropyrazolo[1,5-a]pyrimidine-6-carbonitriles and...     

新型含1,2,3-三唑基[1,2,4](噁)二唑并[4,5-a][1,5]苯并硫氮杂卓化合物的合成

将1,2,3-三唑环结构及1,2,4-噁二唑环等多个药效团结构叠加到同一个硫氮杂卓分子中,为药理及生理活性研究提供较好的先导化合物.反应在三乙胺存在下,用2,4-二芳基-2,3-二氢-1,5-苯并硫氮杂卓与α-氯代-2-苯基-1,2,3-三唑基-4-甲醛肟在室温进行1,3-偶极环加成反应,合成一系列的2-苯基-1,2,3-三唑基[1,2,4]噁二唑并[4,5-a][1,5]苯并硫氮杂卓化合物,并采用红外光谱、核磁共振、元素分析等测试技术对化合物进行了表征.     

新型含1,2,3-三唑基[1,2,4]噁二唑并[4,5-a][1,5]苯并硫氮杂卓化合物的合成

将1,2,3-三唑环结构及1,2,4-噁二唑环等多个药效团结构叠加到同一个硫氮杂卓分子中,为药理及生理活性研究提供较好的先导化合物。反应在三乙胺存在下,用2,4-二芳基－2,3－二氢－1,5-苯并硫氮杂卓与α-氯代-2－苯基－1,2,3-三唑基4－甲醛肟在室温进行1,3-偶极环加成反应,合成一系列的2－苯基－1,2,3-三唑基[1,2,4]噁二唑并[4,5－a][1,5]苯并硫氮杂卓化合物,并采用红外光谱、核磁共振、元素分析等测试技术对化合物进行了表征。     

Synthesis and reactions of sym-Triazolo-[1,5-a]-sym-Triazinonethiones

1-Carbethoxythiocarbamoyl-5-amino-1,2,4-triazoles and N-(1,2,4-triazol-5-yl)-N-carbethoxythioureas are formed in the reaction of 5-amino-1,2,4-triazoles with carbethoxyisothiocyanate. The triazole derivatives obtained are cyclized to substituted sym-triazolo-[1,5-a]-sym-triazines in alkaline media.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 276–280, February, 1973.See also [1,2].     

Synthesis of podands functionalized with 2-oxo(sulfanylidene)-1,2,3,4-tetrahydropyrimidine and 4,7-dihydrotetrazolo[1,5-a]pyrimidine fragments

Russian Journal of Organic Chemistry - Podands functionalized with 2-oxo(sulfanylidene)-1,2,3,4-tetrahydropyrimidine and 4,7-dihydrotetrazolo[1,5-a]pyrimidine fragments were synthesized by...