Synthesis of 7-Amino-3-tert-butyl-2-alkylthiopyrrolo[1,2-b][1,2,4]triazine-6-carboxylates

Russian Journal of General Chemistry - Alkylation of tert-butyl-7-amino-3-tert-butyl-8-R1-2-oxo-1,2-dihydropyrrolo[1,2-b][1,2,4]triazin-6-carboxylates with alkyl halides R2Br (R1 = CN, CO2Et; R2 =...     

Reactivity of 7-amino-3-tert-butyl-4-oxo-4,6-dihydropyrazolo[5,1-c][1,2,4]triazine-8-carbonitrile

By reaction of carbonyl compounds with 7-amino-3-tert-butyl-4-oxo-4,6-dihydropyrazolo[5,1-c]-[1,2,4]triazine-8-carbonitrile 3-tert-butyl-8-R-4,6,9,10-tetrahydropyrimido[4′,5′:3,4]pyrazolo[5,1-c][1,2,4]-triazine-4,10-diones and (3-tert-butyl-4-oxo-8-cyano-4,6-dihydropyrazolo[5,1-c][1,2,4]triazin-7-yl)acetamide were obtained.     

Synthesis of 3-amino-5H-pyrimido[5,4-b]indol-4-one derivatives

Starting with ethyl 3-aminoindole-2-carboxylate, the synthesis of 3-amino-5H-pyrimido[5,4-b]indole-2,4-dione 5 , 3-amino-5H-pyrimido[5,4-b]indol-4-one 10 and some related compounds is described. Preliminary results about the inhibition of platelet aggregation by these compounds is reported.     

Conversion of 2-amino-3-phenyl-4-quinolone to 1H-2,3-dihydro-2,9-dioxo-10-phenylimidazo[1,2-a]quinoline

1H-2,3-Dihydro-2,9-dioxo-10-phenylimidazo[1,2-a]quinoline has been obtained from 2-amino-3-phenyl-4-quinolone by acylation with chloroacetyl chloride and cyclization of the intermediate 2-di(chloroacetyl)amino-3-phenyl-4-chloroacetoxyquinoline. The reaction of the latter with morpholine was studied.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 388–390, March, 1990.     

[3 + 2]-Cycloaddition of azomethine ylide at 1,3-dimethyl-6-(2-oxo-1,2-dihydro-3H-indol-3-ylidene)-3a,9a-diphenyl-3,3a,9,9a-tetrahydroimidazo[4,5-e][1,3]thiazolo[3,2-b][1,2,4]triazine-2,7(1H,6H)-diones

[3 + 2]-Cycloaddition of azomethine ylide generated from formaldehyde and sarcosine at the double bond of 1,3-dimethyl-6-(2-oxo-1,2-dihydro-3H-indol-3-ylidene)-3a,9a-diphenyl-3,3a,9,9a-tetrahydroimidazo[4,5e][1,3]thiazolo[3,2-b][1,2,4]triazine-2,7(1H,6H)-diones occurs stereospecifically at the face opposite to the phenyl substituents. Product 3a crystallizes as a conglomerate.     

Synthesis and reactivity of ethyl 7-amino-3-tert-butyl-4-thioxo-4,6-dihydropyrazolo[5,1-c][1,2,4]triazine-8-carboxylate

Treatment of ethyl 7-amino-3-tert-butyl-4-oxo-4,6-dihydropyrazolo[5,1-c][1,2,4]triazine-8-carboxylate with P₂S₅ in pyridine gave ethyl 7-amino-3-tert-butyl-4-thioxo-4,6-dihydropyrazolo[5,1-c][1,2,4]triazine-8-carboxylate which was subjected to acylation, decarboxylation, and hydrazinolysis.     

Cyclocondensation of 3-amino-2-iminonaphtho[1,2-d]thiazole with oxalic acid derivatives

Refluxing 3-amino-2-iminonaphtho[1,2-d]thiazole ( 1 ) with diethyl oxalate ( 2a ) in a 2:1 molar ratio in dry pyridine provided 2,2′-binaphtho[1′,2′:4,5]thiazolo[3,2-b][1,2,4]triazole ( 3 ). On the other hand, when 1 was treated with excess amount of 2a in dimethylformamide, it afforded ethyl naphtho[1′,2′:4,5]thiazolo[3,2-b][1,2,4]triazole-2-carboxylate ( 4a ) on heating and ethyl N-(2-iminonaphtho[1,2-d]thiazol-3-yl)oxamate ( 5 ) by stirring at room temperature. Cyclization of 5 upon fusion led to the formation of 3-hydroxy-2H-naphtho-[1′,2′:4,5]thiazolo[3,2-b][1,2,4]triazin-2-one ( 6 ). Compound 6 could also be prepared directly from 1 by refluxing either with 2a neatly, in glacial acetic acid or with oxalic acid ( 2b ) in the same medium. The acid form of 4a might be obtained from 1 and 2b on heating in dimethylformamide, but it was decarboxylated to naphtho-[1′,2′:4,5]thiazolo[3,2-b][1,2,4]triazole ( 4b ) during the reaction.     

1,4-Dihydropyridine-3,5-di-and 2-methyl-4-aryl-5-oxo-4,5-dihydro-1H-indeno[1,2-b]pyridine-3-carbothionic acid ethyl esters

Methods for the synthesis of 1,4-dihydropyridine-3,5-di- and 4-aryl-5-oxo-4,5-dlhydro-1H-indeno[1,2-b]pyridine-3-carbothionic acid ethyl esters were developed. A comparative analysis of the physicochemical characteristics of this series of substances is given.Their reactivities in electrochemical and chemical oxidation reactions were studied. The electrochemical oxidation potentials of the thionic acid esters are found in a lower anodic range as compared with their oxygen analogs. According to the ionization constants, the thionic acid esters of 4,5-dihydroindenopyridines are stronger acids than the carbonyl esters; this is explained by participation of the free 3d orbitals of the sulfur atom in stabilization of the anion.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No.2, pp. 210–216, February, 1984.     

3-Phenacylidene-3,4-dihydro-1H-pyrido[2,3-b]pyrazin-2-ones and 2-Phenacylidene-1,2-dihydro-4H-pyrido[2,3-b]pyrazin-3-ones

Condensation of 2,3-diaminopyridine ( 1 ) with ethyl o-, m- and p-substituted benzoylpyruvates 2–9 gave two isomeric products. The preferential formation of one or the other isomer has been achieved by different reaction conditions. All the products appear to exist in the enamine form as evidenced by their ¹H nmr and ir spectra.     

Cyclocondensation of 3-amino-2-iminonaphtho[1,2-d]-thiazole with α-ketocarboxylic acid derivatives: Synthesis of 2-substituted 3-Oxo-3H-naphtho[1′,2′:4,5]thiazolo-[3,2-b][1,2,4]triazines as potential anti-HIV agents

The cyclocondensation of 3-amino-2-iminonaphtho[1,2-d]thiazole ( 1 ) with a series of α-keto mono- and dicarboxylic acid derivatives 5a-i under different conditions was investigated. When the experiments were performed by refluxing in glacial acetic acid, the corresponding cyclized products, 2-substituted 3-oxo-3H-naphtho[1′,2′:4,5]thiazolo[3,2-b][1,2,4]triazines 4 were obtained in fair to good yields. On the other hand, when the reaction was conducted in boiling ethanol, it gave only the open chain condensates 6 , or in rare cases, together with minor amount of 4 . Since the intermediates 6 exist as mixture of both E- and Z-isomers, cyclization through heating was found insufficient. In any event representative compounds 4b,g,i have been evaluated for anti-HIV activity, but none of them were active.     

Facile synthesis of [1,2,4]triazino[4,3-b][1,2,4,5]tetrazepin derivatives by a one-pot reactions using 4-amino-3-hydrazinyl-6-methyl-1,2,4-triazin-5 (4H)-one

<正>4-Amino-3-mercapto-6-methyl-l,2,4-triazin-5(4H)-one 1 converted to 4-amino-6-methy-3-(methylthio)-1,2,4-triazin-5(4H)-one by methylation with methyl iodide.Controlled hydrazination of the resulting compound afforded 4-amino-3-hydrazinyl-6- methyl-l,2,4-triazin-5(4H)-one 2 as a building block,to the synthesis of some novel derivatives of[1,2,4]triazino- [4,3,b][1,2,4,5]tetrazepine 3-6,by the reaction with 3-chloropentane-2,4-dione,chloro acetonitrile,1,3-dichloroacetone,and methyl bromoacetate.This general synthetic procedure can be extended to the preparation of wide variety of tetrazepines using 1,2- bielectrophiles derivatives.     

Facile synthesis and antifungal activity of 3-substituted 4-amino-8-ethoxycarbonylpyrazolo[5,1-c][1,2,4]triazines and pyrazolo[1′,5′:3,4][1,2,4]triazino[5,6-b][1,5]benzodiazepines

The reactions of the pyrazole-5-diazonium salt 3 with malononitrile and ethyl cyanoacetate gave 4-amino-3-cyano-8-ethoxycarbonylpyrazolo[5,1-c][1,2,4]triazine 7 and 4-amino-3,8-bisethoxycarbonylpyrazolo[5,1-c]-[1,2,4]triazine 8 , whose reactions with p-chloroaniline hydrochloride afforded 4-amino-8-ethoxycarbonyl-3-(p-chlorophenyl)amidinopyrazolo[5,1-c][1,2,4]triazine 9 and 4-amino-8-ethoxycarbonyl-3-(p-chlorophenyl)car-bamoylpyrazolo[5,1-c][1,2,4]triazine 10 , respectively. The reactions of 7 and 8 with o-phenylenediamine di-hydrochloride provided 9-ethoxycarbonyl-13H-spiro[benzimidazole-2′(3′H),6(5H)-pyrazolo[1,5′:3,4][1,2,4]tri-azino[5,6-b][1,5]benzodiazepine] hydrochloride 11a and 9-ethoxycarbonyl-6-oxo-13H-5,6-dihydropyrazolo-[1′,5′:3,4][1,2,4]triazino[5,6-b][1,5]benzodiazepine 12 , respectively. The antifungal activity of the above compounds was described.     

Formation of 2,3-dihydro-3-chloromethylnaphtho[1,2-b][1,4]-dithiane in the reaction of allyl 1-naphthyl sulfide with sulfur dichloride

Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1429–1430, October, 1990.     

One-Pot Four Component Synthesis of 3-Amino-1-(1H-indol-2-yl)-5,10-dioxo-5,10-dihydro-1H-pyrazolo[1,2-b]phthalazine Derivatives Mediated by [DBUH][OAc]

Russian Journal of General Chemistry - One-pot, four component, green, and efficient synthesis of 3-amino-1-(5-nitro-1H-indol-2-yl)-5,10-dioxo-5,10-dihydro-1H-pyrazolo[1,2-b]phthalazine derivatives...     

Synthesis of 3-carboethoxy-4,11-dihydro-11-alkyl/phenyl-4-oxopyrimido[1,2-b][1,2,4]benzothiadiazine 6,6-dioxides. A novel heterocyclic ring system

The synthesis of some novel 3-carboethoxy-4,11-dihydro-11-alkyl/phenyl-4-oxopyrimido[1,2-b][1,2,4]benzo-thiadiazine 6,6-dioxides ( IVa-c ) from 3-amino-4-alkyl/phenyl-4H-1,2,4-benzothiadiazine 1,1-dioxides ( 1a-c ) and diethyl ethoxymethylenemalonate ( II ) is described. The compounds have been screened for their antibacterial activity.