Synthesis of new 4-phosphorylated derivatives of 5-amino-1,3-oxazole

The N-1,1,1,2-Tetrachloroethylamides were found to react with diethyl amidophosphites via the Arbuzov reaction to afford N-substituted amides of ethyl 1-acylamino-2,2,2-trichloroethylphosphonic acids. A convenient method for the synthesis of new 4-phosphorylated 5-amino-1,3-oxazoles on their basis was developed.     

Synthesis of novel 1,3-oxazole derivatives with insect growth-inhibiting activities

Straightforward and direct synthesis of 2-substituted-5-oxazolecarbaldehydes was achieved by treating propargylamides with mercury（II）perchlorate as catalyst and ammonium cerium（IV）nitrate as oxidant agent through intramolecular cyclization.These structurally interesting outcomes beneft to synthesize2,5-disubstituted-1,3-oxazoles with armyworm growth regulating activities.     

Recyclization of the products of amidine addition to the substituted 5-amino-4-cyano-1,3-oxazole into new derivatives of 5,6-Diaminopyrimidin-4-one

The products of addition of amidines to accessible 5-arylamino-4-cyano-1,3-oxazoles at heating in acetic acid undergo recyclization and afford new derivatives of 6-amino-5-acylaminopyrimidin-4-one, whose structure was reliably established using X-ray diffraction studies.     

Synthesis of 5-amino-1,3-dimethylpyrazol-4-yl aryl ketones

A convenient preparation of 5-amino-1,3-dialkylpyrazol-4-yl heterocyclic ketones is reported. They are prepared from the reaction of heterocyclic esters with the di-lithio derivative from N-(4-bromo-1,3-dimethyl-1H-pyrazol-5-yl)benzamide ( 1 ).     

Synthesis and antiangiogenic activities of 5-amino-1,3-dihydro-1, 3-dioxo-2H-isoindole-2-propanoic acid derivatives

Based on the structure-activity relationships and antiangiogenic mechanism of RGD-containing peptides,a series of 5-amino- 1,3-dihydro-1,3-dioxo-2H-isoindole derivatives were synthesized.The structures were characterized by ~1H NMR,MS and elementary analysis.There ability to inhibit angiogenesis were evaluated by chick embryo chorioallantoic membrane assay at 10~(-5) mol/L.Compounds 7a and 7b displayed obvious antiangiogenic activity.     

Synthesis and biological activities of novel 2-amino-1,3-thiazole-4-carboxylic acid derivatives

A series of novel 2-amino-1, 3-thiazole-4-carboxylic acid derivatives were designed and synthesized. Their structures were confirmed by melting points, IR, ¹H NMR, ¹³C NMR, and HRMS or elemental analysis. Biological activities of all title compounds including fungicidal activity and antivirus activity were evaluated systematically. Preliminary bioassays indicated that these compounds exhibited good fungicidal activity at 50 μg/mL, compounds 4b and 4i exhibited over 50% activity against six fungi tested. Most compounds showed good activity against TMV with different models in vivo at 100 μg/mL. Compounds 4c and 4e stood out with high effects against TMV in vivo in all models tested, including protective, inactivative, curative, and inductive activities. These data demonstrate a new strategy for fungi and virus control.     

Das 1,3-Dimethyl-4-amino-5-nitrosouracil

Ohne Zusammenfassung     

Transformation of substituted 5-amino-1,3-oxazole-4-carbonitriles into new 3,4,5-triaminopyrazole derivatives

Reactions of accessible 5-alkylamino- and 5-arylamino-1,3-oxazole-4-carbonitriles with hydrazine hydrate on heating involved a complex transformation sequence resulting in the formation of 3,4,5-triaminopyrazole derivatives. The structure of the products was confirmed by their cyclocondensation with acetylacetone, leading to 2-alkyl(aryl)amino-3-acylamino-5,7-dimethylpyrazolo[1,5-a]pyrimidines which were identified by NMR spectroscopy using COSY, NOESY, HMQC, and HMBC techniques.     

Synthesis and properties of 4-phosphorylated derivatives of 5-hydroxyalkylamino-1,3-oxazoles

Reactions of derivatives of diethyl 1-acylamino-2,2,2-trichloroethylphosphonates with different pharmacophore aminoalkanols afforded new 5-hydroxyalkylamino-1,3-oxazole derivatives. The latter are promising substrates for producing new 4-phosphorylated peptidomimetics containing alcohol residues.     

Synthesis of 3′, 4′-dihydronaphth-1′, 2′ ∶ 5, 4-oxazole and its 2-aryl derivatives

From 2-amino-1-keto-1, 2, 3, 4-tetrahydronaphthalene, prepared by reduction of isonitroso--tetralone, a number of N-acyl derivatives are prepared, and these are converted further to 2-substituted 3, 4-dihydronaphth-1, 25, 4-oxazoles,     

Synthesis of substituted 2-amino-4H-1,3-oxazines

4,4,6-Trimethyl-2-methylarylamino-4H-1,3-oxazines were synthesized by intramolecular cyclization of N-oxoalkyl-S-methylisothioureas.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 764–767, June, 1974.     

Mechanism of the recyclization of 2-amino-5-benzylidene-1,3-thiazol-4(5H)-one into derivatives of 2-amino-5-benzylidene-1,5-dihydro-4H-imidazol-4-one

Mechanisms are given for reactions taking place upon heating 2-amino-5-benzylidene-1,3-thiazol-4(5H)-one in a medium consisting of a secondary amine. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 111–114, January, 2008.     

Synthesis and some properties of 4-phosphorylated derivatives of 5-mercapto-1,3-oxazoles

Various approaches to the synthesis of new derivatives of diethyl 5-mercapto-2-R-1,3-oxazole-4-ylphosphonates were considered. The behavior of these compounds in the presence of mineral acids and alkalis resulting in the synthesis of previously unknown 5-mercapto-2-R-1,3-oxazole-4-ylphosphonic acids was studied.     

Synthesis of new imidazo[4,5-d][1,3]diazepine derivatives from 5-amino-4-(cyanoformimidoyl)imidazoles

N¹-[(Z) -2- Amino-1,2-dicyanovinyl]formamidines 1a-d react readily with tosyl isocyanate to form novel 8-amino-3-substituted-5-oxo-7-tosylaminoimidazo[4,5-d][1,3]diazepines 6a-d rather than the 6-cyano-2-oxopurine derivatives 5a-d expected. Compound 5a has been synthesized from 1a by reaction with ethyl chloroformate and base-catalyzed cyclization of the resultant 5-ethoxycarbonylamino-4-(cyanoformimidoyl)imidazole. Treatment of the 5-amino-4-cyanoimidazoles 7a and b with tosyl isocyanate under similar conditions gives the 4-cyano-5-(3′-tosylureido)imidazoles 8a and b , which on treatment with ethanolic ammonia cyclizes to the corresponding isoguanines 10a and b .     

Synthesis of 4-aminopyrazolo[3,4-d]pyrimidine derivatives from 5-acetyl-6-amino-4-methylsulfanyl- or 5-acetyl-6-amino-4-methylsulfonylpyrimidines

Diacetyl ketene N,S-acetal was used for the synthesis of 5-acetyl-6-amino-4-methylsulfanylpyrimidines substituted at the exocyclic nitrogen atom, which were further oxidized with m-chloroperbenzoic acid to the corresponding methylsulfonylpyrimidines. Reactions of hydrazines with these pyrimidines containing vicinal Ac and MeS (or MeSO₂) groups were used for the preparation of new 4-aminopyrazolo[3,4-d]pyrimidine derivatives.     

Synthesis of 5-amino-6-nitro-1,2,3,4-tetrazine 1,3-dioxide

5-Amino-(tert-butyl-NNO-azoxy)-1,2,3,4-tetrazine 1,3-dioxide reacts with nitronium tetra-fluoroborate to give 5-amino-6-nitro-1,2,3,4-tetrazine 1,3-dioxide. This compound is of interest as a new energetic material. A plausible reaction mechanism involves electrophilic substitution of the tert-butyl-NNO-azoxy group by the nitro group.

     

Synthesis of 6-nitro-4-sulfanyl-1H-indole derivatives from 2,4,6-trinitrotoluene

The synthesis of 6-nitro-4-sulfanyl-1H-indoles from 2,4,6-trinitrotoluene (TNT) is described. The first step is the nucleophilic substitution of an ortho-nitro group with a thiol to give the corresponding sulfide. The latter were transformed into the corresponding enamines upon treatment with dimethylformamide dimethyl acetal (DMF DMA). The enamines were converted into the indoles applying the Batcho–Leimgruber synthetic protocol.