1.2.4- Triazole, 1,3-dichloro

Bis(3,4-diethyl-2-pyrrolylmethyl)-3,4-dietliyl-l//-pyrrole (2), prepared in situ from the di-t-butylester of the 5,5 -dicarboxylic acid (/), reacts with 4//-1,2,4-triazole-3,5-dialdehyde (3) in di-chloromethane in the presence of trifluoroacetic acid and 2,3-dichloro-5,6-dicyano-/)-benzoquino-ne as an oxidation reagent. Dark blue crystals are obtained after chromatographic purification. The dark violet chloroform solution fluoresces purple at 360 nm and gives the NMR experiments 39. Which compound and which tautomer of it has been formed ... 

Ethyl a,2-dichloro-5-[4-(difluoromethyl)-4,5-dihydro-3-methyl-5-0X0-1H-1,2,4-triazol-1-yl]-4-fluorobenzene-propanoate... 

Reactivity of azides towards acetylenedicarboxylates is very dependent on their electron density (energy HOMO). Thus, strongly electron-deficient 3,5-dicyano-2,4,6-triazidopyridine 1039 reacts slowly with dimethyl acetylenedicarboxylate to give triazole derivative 1038 in 34% yield with most of the starting material recovered unchanged. Under comparable conditions, less electron-deficient 3,5-dichloro-2,4,6-triazidopyridine 1040 reacts with dimethyl acetylenedicarboxylate to provide 2,6-bis(l,2,3-triazol-lyl)pyridine derivative 1041 in 75% yield (Scheme 171) <2001CHE861>. 

As part of a program directed toward the synthesis of dendrimeric structures containing the 1,2,4-triazole moiety, 3,5-dichloro-4(4-methoxyphenyl)-4/7-l,2,4-triazole 69 was reacted with phenol 77 under basic conditions to give the dendron 78 in a yield of 80% (Equation 28) <2006T2677>. 

Base-catalyzed cyclization of semicarbazide 189 gave the triazolidine 3,5-dione 190, subsequent treatment of which with phosphorus oxychloride gave 3,5-dichloro-4-aryl-l,2,4-triazole 191 (Scheme 17). <2006T2677>. 

Acrylonitrile 3 - Amino-1,2,4-triazole Carbon tetrachloride Chloroform 1,4-Dichloro-2-butene Dioxane Epichlorohydrin Ethylene dibromide Ethylenethiourea Lead chromate Methylenedianiline Styrene... 

Ring substituents can have a considerable effect on the acidity of the system. In the 1,2,4-triazole series a 3-amino group decreases the acidity to 11.1, a 3-methyl group to 10.7, whereas a 3-phenyl group increases the acidity to 9.6, and 3,5-dichloro substitution to 5.2 (71PMH(3)l). 

The reactions of 7-chloro-pyrimido[5,4-/][l,2,4]triazolo[3,4- ]l,3,4] thiadiazepines 81a-c with different nucleophiles were described in order to obtain new derivatives with possible antitumor activity <2003MI46>. The substituted 81a-c were prepared by cyclocondensation of 4,6-dichloro-2-methylthiopyrimidine-5-carbaldehyde 82 with the corresponding 3-substituted 4-amino-l,2,4-triazole-5-thiones 83. The different reactions as well as the corresponding yields are described in Scheme 8. Interestingly, hydrolysis occurred even during 111 NMR experiments in DMSO at 80 °C. 

A mixture of l-(4-hydroxyphenyl)-4-(l-methylethyl)piperazine, cis-[2-(2,4-dichloro-phenyl)-2-(lH-l,2,4-triazol-l-ylmethyl)-l,3-dioxolan-4-ylmethyljmethanesulfonate, potassium carbonate and N,N-dimethylformamide is stirred and heated overnight at 120°C. The reaction mixture is cooled and poured onto water. The product is extracted twice with dichloromethane. The combined extracts are washed twice with a potassium carbonate solution, dried, filtered and evaporated. The residue is taken up in methanol and a sodium methanolate solution 30% are added. The whole is stirred and refluxed for 1 h. The mixture is poured onto water and the layers are separated. The organic phase is dried, filtered and evaporated. The cis-l-(4-((2-(2,4-dichlorophenyl)-2-(lH-l,2,4-triazol-l-ylmethyl)-l,3-dioxolan-4-yl)methoxy)phenyl)-4-(l-methylethyl)piperazine was obtained, melting point 116.3°C. 

Chemical Name l-(2,4-dichloro-p-propylphenylethyl)-l//-l,2,4-triazole l-[2-(2,4-dichlorophenyl)pentyl]-l//-l,2,4-triazole... 

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