Research on arylhydrazones of substituted glyoxylic acids

Substituted 2-benzalhydrazono-3-phenyl-4-(arylhydrazonochloroformyl)-4-thiazo-lines and 2,2′-azinobis[3-aryl-4-(arylhydrazonochloroformyl)-4-thiazolines], respectively, are formed in the condensation of arylhydrazones of chloromethylgly-oxyloyl chloride with 4-phenylthiosemicarbazones and 1, 6-diarylhydrazodithiocar-bonamides.     

Reactions of 1-glucosyl-5-nitro-1,2,4-triazole with nucleophiles

1-Glucosyl-5-nitro-1,2,4-triazole reacted with nucleophiles, such as water, aziridine, chloride ion and 4-dimethylaminopyridine to give the corresponding 5-substituted 1-glucosyl-1,2,4-triazole derivatives.     

Syntheses of substituted-1,2,4-triazoles

Starting from the readily available 3-phenylpropionitrile, 3-(or 5-)(2-phenethyl)-1,2,4-triazole 3 was prepared. Reaction of compounds 3 with diazomethane afforded 1-methyl-3-(2-phenethyl)-1,2,4-triazole (4) and 1-methyl-5-(2-phenethyl)-1,2,4-triazole (5) . Reaction of compound 3 with methanesulfonyl chloride, benzenesulfonyl chloride or p-toluenesulfonyl chloride afforded only one of the expected isomer; namely compounds 6 , 7 and 8 respectively.     

Synthesis and determination of pKa values of some new 3,4-disubstituted-4,5-dihydro-1H-1,2,4-triazol-5-one derivatives in non-aqueous solvents

3-Alkyl(Aryl)-4-amino-4,5-dihydro-1H-1,2,4-triazol-5-ones (2) reacted with 2-furoyl chloride and thiophene-2-carbonyl chloride to afford the corresponding 3- alkyl(aryl)-4-(2-furoylamino)-4,5-dihydro-1H-1,2,4-triazol-5-ones (3) and 3-alkyl(aryl)- 4-(2-thienylcarbonylamino)-4,5-dihydro-1H-1,2,4-triazol-5-ones (4), respectively. The new compounds synthesized were characterized by using IR, 1H-NMR, 13C-NMR and UV spectral data together with elemental analysis. In addition, to investigate the effects of solvents and molecular structure upon acidity, compounds 3 and 4 were titrated potentiometrically with tetrabutylammonium hydroxide in four non-aqueous solvents (isopropyl alcohol, tert-butyl alcohol, N,N-dimethylformamide and acetonitrile). The half-neutralization potential values and the corresponding pKa values were determined for all cases.     

An anomalous acylation of an aminobenzenesulfonamide

Acylation of 2-amino-4-chlorobenzenesulfonamide by 2-acetoxyisobutyryl chloride under acidic conditions unexpectedly gave 6-chloro-3-methyl-4H-1,2,4-benzothiadiazine 1,1-dioxide and 8-ehloro-2,2,3a-trimethyl-3a,4-dihydrooxazolo[2,3-b] [1,2,4]benzothiadiazin-1-one 5,5-dioxide, the skeletons of which incorporate the carbon atom of the acetoxyl carbonyl group of the acid chloride.     

Modification of Gold Electrode via Electrografting of the in situ Generated 3‐Carboxy‐1,2,4‐triazoldiazonium Salt for Label‐free Determination of Carcinoembryonic Antigen

In present study electrografting of the in situ generated 3‐carboxy‐1,2,4‐triazoldiazonium chloride on the Au disk electrode have been studied. The electrode film thickness differences between electrodeposited due to the aryl radical structure 3‐carboxy‐1,2,4‐triazoldiazonium chloride and 4‐carboxyphenyldiazonium salt was shown. The mechanism of 3‐carboxy‐1,2,4‐triazoldiazonium chloride electrografting has been proposed. 4‐nitroanilin was used to investigate the carbodiimide crosslinking capacity. It was established that electrodeposited films are suitable for carbodiimide crosslinking but the reaction proceed only on the “external” electrografted layer. Under the chosen optimal parameters, the label‐free electrochemical immunosensor have been developed. 3‐carboxy‐1,2,4‐triazoldiazonium chloride electrografting provided improvement of analytical characteristics in respect to electrodeposited 4‐carboxyphenyldiazonium salt. The linear range for carcinoembryonic antigen (CEA) detection is 10–10⁴ ng ? ml^?1, the limit of detection estimated as 0.2 ng ? ml^?1. The developed immunosensor is stable during 30 day′s storage and selective against excess of bovine serum albumin as an interfering reagent.     

A new method for the synthesis of novel 1-aryl-3-heteroaryl-1H-pyrazolo[3,4-b]quinoxalines

The reaction of 3-(2,3-dihydro-4-methyl-3-thioxo-4H-1,2,4-triazol-5-ylmethylene)-2-oxo-1,2,3,4-tetrahydroquinoxaline 4 with o-chlorobenzenediazonium chloride gave 3-[α-(o-chlorophenylhydrazono)-2,3-dihydro-4-methyl-3-thioxo-4H-1,2,4-triazol-5-ylmethyl]-2-oxo-1,2-dihydroquinoxaline 6 , whose refluxing in phosphoryl chloride/pyridine afforded 1-(o-chlorophenyl)-3-(2,3-dihydro-4-methyl-3-thioxo-4H-1,2,4-triazol-5-yl)-1H-pyrazolo[3,4-b]quinoxaline 7. The reactions of 6 and 7 with nitrous acid resulted in sulfur extrusion to provide 1-(o-chlorophenyl)-3-(4-methyl-4H-1,2,4-triazol-5-yl)1H-pyrazolo[3,4-b]quinoxaline 8 and 3-[α-(o-chlorophenylhydrazono)-4-methyl-4H-1,2,4-triazol-5-ylraethyl]-2-oxo-1,2-dihydroquinoxaline 9 , respectively.     

Conversion of 4-amino-4H-1,2,4-triazole to 1,3-bis(1H-azol-l-yl)-2-aryl-2-propanols and 1-phenacyl-4-[(benzoyl or 4-toluenesulfonyl)-imino]-(1H-1,2,4-triazolium) Ylides

A series of 1,3-bis(1H-azol-1-yl)-2-aryl-2-propanols 17 were synthesized in an one-pot procedure by reacting l-aryl-2-(1H-1,2,4-triazol-l-yl)- or l-aryl-2-(1H-imidazol-l-yl)ethanones with dimethylsulfoxonium methide in the presence of either 1,2,4-triazole or imidazole. The aromatic groups in 17 were either 4-bromo-, 4-chloro-, 2,4-dichloro- or 2,4-difluorophenyl. 4-Amino-4H-1,2,4-triazole was acylated with either benzoyl or 4-toluene-sulfonyl chloride to afford [4-(benzoyl or 4-toluenesulfonyl)amino]4H-1,2,4-triazole. Subsequent alkylations with 4-bromo- or 4-chlorophenacyl bromide produced 1-(4-bromo- or 4-chlorophenacyl)-4-[(benzoyl- or 4-toluenesulfonyl)amino]-1H-1,2,4-triazolium bromides. Neutralizations of these salts provided the corresponding ylides.     

Alkylation of acyl and sulfonyl derivatives of 3,5-diamino-1-phenyl-1,2,4-triazole

Alkylation of 3-acylamino-, 5-amino-1-phenyl-3-tosylamino-1,2,4-triazoles and 3,5-diacetylamino-1-phenyl-1,2,4-triazole in the presence of an equimolar amount of sodium methylate in DMSO occurs regioselectively at the amide (sulfamide) group nitrogen atom. The benzylation of 3-acetylamino-5-amino-1-phenyl-1,2,4-triazole with excess base and benzyl chloride also alkylates the amino group at position 5. Alkylamino-1-R-1,2,4-triazoles can be conveniently prepared by alkylation of the corresponding acetylamino-1,2,4-triazoles in the presence of base and subsequent acid hydrolysis of the N-acetyl-N-alkyl derivatives. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 557–567, April, 2009.     

3-(3,4,5-三甲氧基苯基)-4-氨基-5-取代苄巯基-1,2,4-三唑的合成及其生物活性

3-(3,4,5-三甲氧基苯基)-4-氨基-5-巯基-1,2,4-三唑与取代苄氯反应合成了九个新型3-(3,4,5-三甲氧基苯基)-4-氨基-5-取代苄巯基-1,2,4-三唑(2a～2i),其结构经1H NMR,IR和MS表征.初步生物活性测试结果表明,3-(3,4,5-三甲氧基苯基)-4-氨基-5-对氯苄巯基-1,2,4-三唑(2b)对半夏立枯病菌具有抑制活性.     

Condensation of 1,2,4-Butanetriol with Carbonyl Compounds and Reactions of Hydroxyalkyl-1,3-dioxacyclanes

A mixture of isomers of 2-(1,3-dioxolan-4-yl)ethanol and 1,3-dioxan-4-ylmethanol was prepared by reaction of 1,2,4-butanetriol with paraformaldehyde. This mixture was subjected to O-alkylation, O-acylation, condensation with phenyl isocyanate, and substitution of OH groups for Cl. The relative activity of acetone derivatives of glycerol and 1,2,4-butanetriol in reactions with allyl chloride and benzyl chloride was estimated.     

C–H Arylation using acyl thiourea ligands: Applications in the synthesis of 3,6-diaryl-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazoles

Synthesis of a series of new 3,6-diaryl-[1,2,4]triazolo[3,4-b] [1,3,4]thiadiazoles(5a–o) was achieved by phophine free, C–H arylative cross-coupling of 6-aryl-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazoles(4a–o)with suitably substituted iodoanilines using 1-(2-naphthoyl)-3-(4-bromophenyl)thiourea as a ligand.The requisite triazolothiadiazoles(4a–o) were obtained by the condensation of 4-amino-1,2,4-triazole-3-thiol(3) with suitably substituted aromatic acids in the presence of phosphoryl chloride.     

Reactions of 1-Allenylpyrazole and 1-Allenyl-1,2,4-triazole with Hydrogen Chloride and Metal Chlorides

1-Allenylpyrazole and 1-allenyl-1,2,4-triazole react with hydrogen chloride via proton addition at the pyridine-like nitrogen atom (N² and N⁴, respectively). In the reaction with 1-allenylpyrazole, 1-[(E)-3-chloro-1-propenyl]pyrazole is also formed via regio- and stereoselective addition of hydrogen chloride to the propadienyl group. 1-Allenylpyrazole and 1-allenyl-1,2,4-triazole act as unidentate ligands with respect to Co, Ni, Cu, Zn, Cd, Pd, and Sn, the donor centers being N² and N⁴, respectively. Apart from mononuclear coordination compounds, 1-allenylpyrazole gives rise to polymeric complexes which contain units and blocks formed by the free ligand.     

Die Acylierung von 5-Amino-1 H-1, 2, 4-triazolen. Eine 13C-NMR.-Studie

The Acylation of 5-Amino-1 H-1,2,4-triazoles. A ¹³C-NMR. Study The acylation of 3-substituted-5-amino-1 H-1,2,4-triazoles (1) with methyl chloroformate or dimethylcarbamoyl chloride yielded mainly 1-acyl-5-amino-1,2,4-triazoles ( 2 and 3 ). Acylation of 3-methyl-, 3-methoxy- and 3-methylthio-5-amino-1 H-1,2,4-triazole ( 1b , 1c and 1d ) with methyl chloroformate gave up to 10% of the 1-acyl-3-amino-1,2,4-triazoles. For the unsubstituted 5-amino-1,2,4-triazole (1a) , a (1:1)-mixture of the 3- and 5-isomers 2a and 4 was obtained in dioxane in the presence of triethylamine. No 4-acylated product was detected in contrast to earlier reports. The structures of the reaction products were determined with the aid of proton coupled ¹³C-NMR. spectra using the corresponding N-methyl-1,2,4-triazoles as reference compounds.     

3－苄基－6－（1－氨基烃基）－1，2，4－三唑并[3,4-b]-1,3,4-噻二唑的合成与波谱表征

3－苄基－4－氨基－5－巯基－1，2，4－三唑与氨基酸在三氯氧磷存在下反应 ，合成3－苄基－6－（1－氨基烃基）－1，2，4－三唑并[3,4-b]－1，3，4－噻二 唑，其结构经元素分析、红外光谱、核磁共振氢谱、碳谱、质谱等确证。这是稠杂 环接氨基酸残基的首次报道。     

A study on 4-acylamino-4,5-dihydro-1H-1,2,4-triazol-5-ones

Five novel 3-alkyl-4-phenylacetylamino-4,5-dihydro-1H-1,2,4-triazol-5-ones (2) were synthesized by the reactions of 3-alkyl-4-amino-4,5-dihydro-1H-1,2,4-triazol-5-ones (1) with phenylacetyl chloride and characterized by elemental analyses and IR, 1HNMR, 13C-NMR and UV spectral data. The newly synthesized compounds 2 were titrated potentiometrically with tetrabutylammonium hydroxide in four non-aqueous solvents such as isopropyl alcohol, tert-butyl alcohol, acetonitrile and N,N-dimethylformamide, and the half-neutralization potential values and the corresponding pKa values were determined for all cases. In addition, these new compounds and five recently reported 3-alkyl-4-(pmethoxybenzoylamino)-4,5-dihydro-1H-1,2,4-triazol-5-ones (3) were screened for their antioxidant activities.     

A new method for the synthesis of novel 6-quinoxalinylpyrazolo[5,1-c][1,2,4]triazines

The reaction of the quinoxaline 1 with 4-ethoxycarbonyl-1H-pyrazole-5-diazonium chloride 7 at room temperature gave 3-[α-(4-ethoxycarbonyl-1H-pyrazol-5-ylhydrazono)methoxycarbonylmethyl]-2-oxo-1,2-dihydroquinoxaline 8. The pmr spectrum of 8 in deuteriodimethylsulfoxide supported the presence of two tautomers 8-I and 8-II. Refluxing of 8 in N,N-dimethylformamide or acetic acid resulted in cyclization to afford 8-ethoxycarbonyl-4-oxo-3-(3-oxo-3,4-dihydroquinoxalin-2-yl)-1,4-dihydropyrazolo[5,1-c][1,2,4]triazine 9. Compound 9 was also obtained directly by the reaction of 1 with 7 under reflux in better yield. The reaction of 9 with hydrazine hydrate provided the hydrazinium salt 10 , while the reactions of 9 with triethyl and trimethyl orthoformates in the presence of 1,8-diazabicyclo[5,4,0]-7-undecene produced 8-ethoxycarbonyl-4-ethoxyl-3-(3-oxo-3,4-dihydroquinoxalin-2-yl)pyrazolo[5,1-c][1,2,4]triazine 11a and 8-ethoxycarbonyl-4-methoxyl-3-(3-oxo-3,4-dihydroquinoxalin-2-yl)pyrazolo[5,1-c][1,2,4]triazine 11b , respectively. The chlorination of 11a with phosphoryl chloride gave 3-(3-chloroquinoxalin-2-yl)-8-ethoxycarbonyl-4-ethoxylpyrazolo[5,1-c]-[1,2,4]triazine 12 , whose reaction with morpholine afforded 8-ethoxycarbonyl-4-ethoxyl-3-[3-(morpholin-4-yl)-quinoxalin-2-yl]pyrazolo[5,1-c][1,2,4]triazine 13.     

Efficient synthesis of 1,2,4-dithiazolidine-3,5-diones (dithiasuccinoyl-amines) and observations on formation of 1,2,4-thiadiazolidine-3,5-diones by related chemistry

An efficient synthesis of 1,2,4-dithiazolidine-3,5-diones ( 1 ) from chlorocarbonylsulfenyl chloride ( 3 ) plus O-dimethylaminoethyl-N-alkyl or aryl thiocarbamates ( 4 ) has been worked out. In this synthesis, 1,2,4-thiadiazolidine-3,5-diones ( 5 ) have been shown to arise as low-level by-products, and experiments were conducted to elucidate the mechanism of the side reaction. N,N′-Dimethyl-1,2,4-thiadiazolidine-3,5-dione ( 5a ) was prepared in one step from N,N′-dimethylurea plus 3 , or from 4a plus one equivalent of sulfuryl chloride. A general route to 5 involved reaction of equimolar amounts of isocyanates ( 6 ), isothiocyanates ( 7 ) and sulfuryl chloride followed by hydrolysis of intermediate 9 . Heterocycles reported have been characterized by nmr, ir, uv, ms, and hplc.     

Synthesis of 3,5-Diaryl-4-benzylideneamino-1,2,4-triazoles and 4-Amino-3,5-diaryl-1,2,4-triazoles

A one-pot reaction leading to 3,5-diaryl-4-benzylideneamino-1,2,4-triazoles is described, the key step of which is the reaction of arenecarbohydrazonoyl chloride with benzylidenehydrazide. Compounds obtained in this way were hydrolyzed to 4-amino-3,5-diaryl-1,2,4-triazoles.     

Alkylation,amino(hydroxy)methylation,and cyanoethylation of 5-substituted 4-phenyl-4<Emphasis Type="Italic">H</Emphasis>-1,2,4-triazole-3-thiols

Reactions of 1,2,4-triazole-3-thiols with 2-bromopropionic acid, 2-bromocaproic acid, ethylene chlorohydrine, chloroacetamide, 3-bromo-4-methoxybenzyl chloride, 2-methoxy-5-acetylbenzyl chloride, and 2-(2-chlorophenoxy)ethyl chloride in the presence of KOH have afforded new 3-sulfanyl-1,2,4-triazoles in high yields. Aminomethylation of 1,2,4-triazole-3-thiols in the presence of formaldehyde has given the corresponding 2-aminomethyl-2H-1,2,4-triazole-3(4H)-thiones. Interaction of triazole-3-thiols with formalin and acrylonitrile has resulted in the formation of N²-hydroxymethyl- and 3-(2-cyanoethyl)sulfanyl derivatives.