Synthesis of pyrido[3,2-e]pyrrolo[2,1-c][1,2,4]triazines from pyrido[3,2-e][1,2,4]triazine derivatives

In carrying on our interest in heteropolycyclic structures with biological activities, we projected the preparation of compounds containing the pyrido[3,2-e][1,2,4]triazine or pyrido[2,3-b][1,4]triazepine systems. The established synthetic approach for the preparation of latter system led to the triazine derivatives 5a-f while a new bicyclic triazepine structure 6 is accomplished with difficulty. In expanding the pyridotriazine structure, we obtained derivatives of a new tricyclic structure, 5-substituted-6a-ethyloxycarbonyl-5,6,6a,7-tetrahydropyrido[2,3-e]pyrrolo[2,1-c][1,2,4]triazin-9(8H)-ones 8 in which the triazine ring is fused with a pyrrole nucleus. Compounds 5a-f and 8a,b will be tested as potential CNS depressant, antiinflammatory, analgesic and antibacterial agents.     

Synthesis of New Imidazo[4,5-b]pyridine Derivatives

New imidazo[4,5-b]pyridine derivatives with various substituents in the 2-position (,-unsaturated ketones, imines, ²-pyrazolines, pyrimidines, 1,2,3,4-tetrahydropyrimidines) and derivatives of the new pyrido[3',2':4,5]imidazo[1,2-d][1,2,4]triazine ring system were synthesized. Biological data for selected compounds are presented.     

Synthesis of New Phosphonate Derivatives of Naphtho[2,1-b[Pyran]3,2-e][1,2,4]Triazolo [1,5-c]Pyrimidines

Abstract

The synthesis of new naphthopyranotriazolopyrimidines phosphonates 4a–i in good yields (74%–93%) has been accomplished via Michaelis–Arbusov rearrangement by the reaction of trialkyl phosphite with naphthopyranotriazolopyrimidines chloride 3a–e, which were obtained from α-functionalized iminoethers 1 in two steps. The synthesized compounds 4a–i were completely characterized by IR, ¹H, ¹³C, and ³¹P NMR and HRMS.

Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.     

Synthesis and Antimicrobial Study of New Fused Thiazolo[3,2-b]triazine,Triazolo[4,3-b]triazine,and 1,2,4-Triazinone Derivatives

Russian Journal of Organic Chemistry - 6-[2-(Furan-2-yl)ethyl]-3-sulfanylidene-3,4-dihydro-1,2,4-triazin-5(2H)-one (1) reacted with chloroacetone to give S-acetonyl derivative which cyclized in...     

New Facile Route to Synthesize Furo[3,2-e][1,2,4]triazolo[4,3-c]pyrimidine and Furo[3,2-e][1,2,4]triazolo[1,5-c]pyrimidine Derivatives

A new facile route for synthesis of 3-(aryl)-8,9-diphenylfuro[3,2-e][1,2,4]triazolo pyrimidines derivative from the same starting material, 2-amino-4,5-diphenylfuran-3-carbonitrile, has been developed through heterocyclization of the corresponding arylidene-hydrazono-5,6-diphenylfuro[2,3-d]pyrimidine and N-(arylmethylene)-4-imino-5,6-diphenylfuro[2,3-d]pyrimidin-3(4H)-amine under refluxing condition with acetic anhydride followed by air oxidation. The products were obtained in good yield with an easy workup along with the purification of products by a nonchromatographic method. This general synthetic procedure can be extended to the preparation of a wide range of isomeric triazoles using 2-amino 3-carbonitrile bifunctional derivatives.     

Halo-heterocyclization of trans-5-phenyl-3-cinnamylsulfanyl[1,2,4]triazine into [1,3]thiazino[3,2-b][1,2,4]triazin-9-ium systems

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New synthesis of imidazo[4,5-e][1,3]diazepine

A new approach has been implemented in the synthesis of imidazo-[4,5,-e][1,3]diazepines consisting in the cyclization of 4,5-di-(cholormethyl)imidazole by urea derivatives.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1193–1195, September, 1993.     

Regioselective synthesis of new imidazo[4,5-e][1,3]thiazino[2,3-c][1,2,4]triazines via reaction of imidazo[4,5-e][1,2,4]triazinethiones with ethyl phenylpropiolate

A method for the regioselective synthesis of imidazo[4,5-e][1,3]thiazino[2,3-c][1,2,4]triazine derivatives has been developed by the reaction of imidazotriazinethiones with ethyl phenylpropiolate upon treatment with potassium carbonate or sodium methoxide in methanol. The synthesis was accomplished by Michael-type addition of the imidazotriazinethiones to the triple bond of ethyl phenylpropiolate followed by subsequent intramolecular cyclization.     

Synthesis and rearrangements of 7H-pyrrolo[3,2-e][1,2,4]triazolo[1,5-c]-and 7h-pyrrolo[3,2-e][1,2,4]triazolo[4,3-c]pyrimidines

7H-Pyrrolo[3,2-e][1,2,4]triazolo[1,5-c]pyrimidines were synthesized by the reactions of 2-ethoxymethyleneamino-1H-pyrrole-3-carbonitriles with acid hydrazides and by the reactions of aminoiminopyrimidines (prepared based on the above-mentioned carbonitriles) with acid chlorides. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1438–1443, August, 2006.     

Synthesis of 1,2,4-triazolo[3,2-b]-1,3-thiazines

1,2,4-Triazolo[3,2-b]-1,3-thiazines were obtained by the reaction of 1,2,4,-triazole-3-thiones with an equimolar amount of 1-phenyl-2-cyanoacetylene in the presence of triethylamine or potassium hydroxide. It is shown that triazolethiones form N,S diadducts upon reaction with a twofold excess of cyanoacetylene. The nature of the heteroatom in the exo position of the heteroring affects the direction of addition to phenylcyanoacetylene. 2,4-Bis(1-phenyl-2-cyanovinylene)-1,2,4-triazol-3-one was synthesized.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1051–1053, August, 1982.     

Synthesis of New Thiazolo[3,2-b][1,2,4]triazole Derivatives and Preliminary Evaluation of Their Biological Activity

Russian Journal of General Chemistry - Heterocyclization of 3-[(1H-1,2,4-triazol-3-yl)thio]pentane-2,4-dione afforded 1-(6-methylthiazolo[3,2-b][1,2,4]-triazol-5-yl)ethan-1-one, the reactions of...     

Cascade synthesis of the first imidazo[4,5-e]-thiazolo[2,3-c][1,2,4]triazine derivative

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New synthesis of 5,6-dihydrothiazolo[3,2-b][1,2,4]triazoles

Russian Journal of Organic Chemistry -     

Fluorocontaining Heterocycles: IX. Derivatives of Imidazo[2,1-b][1,3]benzothiazine

The heating of derivatives of benzimidazole-2-thione and imidazolidine-2-thione with tetra(penta)fluorobenzoyl chlorides in toluene or pyridine gave rise to fluorocontaining derivatives of imidazo[2,1-b][1,3]benzothiazine. The latter were studied in reactions of nucleophilic substitution of fluorine for amino groups.     

Synthesis of substituted furo[3,2-e][1,2,4]triazolo[4,3-c]pyrimidines and furo[3,2-e]tetrazolo[1,5-c]pyrimidines

A series of substituted furo[3,2-e][1,2,4]triazolo[4,3-c]pyrimidines and furo[3,2-e]tetrazolo[1,5-c]pyrimidines were obtained from reactions of substituted 2-dimemylamino-4-hydrazmofuro[2,3-d]pyrimidines with orthoesters or sodium nitrite in acetic acid, respectively.     

Synthesis of 5H-5-oxobenzimidazo[2,1-b]pyrido[3,2-e][1,3]thiazine,A novel ring system

Reaction between 2-chloronicotinic acid chloride and 2-mercaptobenzimidazole afforded 5H-5-oxobenzimidazo[2,1-b]pyrido[3,2-e][1,3]thiazine, a novel heterocyclic ring system. The assigned structure was confirmed by means of mass spectrometry.     

Synthesis of Benzofuro[3,2-e][1,4]diazepines

A synthesis of 4-N-oxides and of 3-hydroxy derivatives of 1,3-dihydro-2H-benzofuro[3,2-e][1,4]diazepin-2-ones and of 2,3-dihydro-1H-benzofuro[3,2-e][1,4]diazepines is described. Condensation of 2-acetyl- and 2-benzoyl-3-ethoxycarbonylaminobenzofurans with acrylonitrile gave derivatives of 1,2-dihydro- and of 1,2,3,4-tetrahydrobenzofuro[3,2-b]pyridine.