1,2,3 triazole potassium hydroxide

Triazole (HL) with Me SAuCl, the gold(I) species, in the presence of potassium hydroxide gives the polymeric complexes [AuL] with exobidentate coordination mode of the azolate ligand (79IC658). 

An alternative procedure, again using microwave irradiation but in the presence of aqueous potassium hydroxide and silica, caused cyclization of semicarbazide derivatives 185 to give 3-mercapto-l,2,4-triazoles 186a-f in high yields (Equation 58 and Table 39) <2006PS(181)1839>. 

In the case of 2-amino-1,3,4-oxadiazoles, an external N-nucleophile is not necessary for their conversion into the corresponding triazole derivatives the reaction occurred in ethanol in the presence of potassium hydroxide (Equation 5) <2003BML769>. 

The reaction of compound 376 with hydrazine gives product 377 that has been transformed into similar triazoles 378, after reaction with carbon disulfide in the presence of alcoholic potassium hydroxide, benzoic acid in the presence of phosphoms oxychloride, or 3-[bis-(methylthiomethylene)]pentan-2,4-dione and l,l-dicyano-2,2-dimethylthioethylene, in refluxing -butanol (Scheme 40) (Table 55) <2000FES641>. 

Dichlorophthalazine on condensation with thiosemicarbazide in DMF afforded l,4-bis(thiosemicarbazi-do)phthalazine 444, that undergoes cyclization with carbon disulfide in the presence of potassium hydroxide to give l,4-bis(3, 5 -dithioxy-[l,2,4]triazol-l-yl)phthalazine 445. Compound 445 reacts with monochloric acid in the presence of NaOH to give l,4-bis-(l -thioxy-6 -oxo-[l,2,4]triazolo[3,4-A]-l,3-thiazol-2 -yl]phthalazine 446 (Scheme 51) <2001IJC(B)500>. 

Transformations of 5-substituted 3-mercapto-4-amino[l,2,4]triazoles 143 with bromomalonitrile are shown in Scheme 27. These reactions were carried out in ethanolic potassium hydroxide to yield A -phthalazinemethylene 144a, <2003PS1987> substituted 1-naphthyl-1-ethyl 144b, <2002HAC199> and 2-naphthyloxymethyl derivatives 144c, 2001PS223>. 

As with the reaction of pyrroles, diazoles and triazoles react with propargyl bromide to yield TV-substituted products and, depending upon the base strength, either TV-prop-2-ynylazoles or allenic derivatives are formed [30]. Generally, with potassium carbonate under soliddiquid two-phase conditions at room temperature in the absence of a solvent, the prop-2-ynyl compounds are formed as sole products, whereas with solid potassium hydroxide at elevated temperatures the allenes are obtained as the major products. Benztriazole produces a mixture of the N1- and N2-prop-2-ynyl, and N2-allenic derivatives, whereas with potassium hydroxide only the N -allenic derivative is obtained. The alkynes readily isomerize to the allenes in the presence of base and the quaternary ammonium salt, or upon treatment with methanolic sodium hydroxide. A series of l-(alk-2-ynyl)imidazoles have been prepared, as intermediates in the synthesis of imidazopyridines [31 ] and the reaction of 3-hydroxymethylpyrazoles with propargyl bromide leads to pyrazolooxazines [32]. 

Formaldehyde, Methylnitramine, Methylene chloride, Magenesium sulfate. Sulfuric acid. Chloroform, Hexane Nitric acid. Diethanolamine, Ethanol, Ether, Acetone Potassium permanganate, 3-Amino-l,2,4-triazole, Sodium hydroxide. Sodium bisulfite. Hydrochloric acid. Nitric acid, Acetic anhydride. Acetone... 

Potassium permanganate, 3-Amino-l,2,4,triazole, Sodium hydroxide. Sodium bisulfite. Hydrochloric acid, Nitric acid. Acetic anhydride. Acetone... 

The precursory l,2,4-triazole-3-diazonium nitrate is extremely unstable, even in ice-cold aqueous solution, and no attempt was made to isolate the title diazo compound from its solution, prepared by cautious treatment of the cold diazonium nitrate solution with dilute aqueous potassium hydroxide with cooling. 

Tricyclohexyltin chloride is converted to the hydroxide with sodium hydroxide. The triazole can be prepared from the chloride with sodium or potassium hydroxide and 1,2,4-triazole. 

The cleavage of the 1,2,4-triazolidine-3,5-diones prepared with 3//-l,2,4-triazole-3,5(4//)-diones requires prolonged treatment with potassium hydroxide in refluxing water-ethylene glycol35 or reduction by lithium aluminum hydride in refluxing tetrahydrofuran36. The 1,2,4-triazolidine-3,5-dione derived from 4-(4-nitrophenyl)-3//-l,2,4-triazole-3,5(4/f)-diones should be more easily hydrolyzed 31. The hydrazinolysis of the 1,2,4-triazolidine-3,5-diones should also be a useful and mild procedure38. 

In this series of compounds (5) and its derivatives have been the most extensively studied. The parent compound is stable towards mineral acid but in the presence of 4.5N potassium hydroxide solution [l,2,4]triazolo[5,l-a]isoquinoline (7) was obtained. The mechanism for this conversion is similar to that for isomerization of [l,2,4]triazolo[4,3-n]pyridines described earlier and is given in Scheme 3 (71RTC1225). Oxidation of both (5) and (7) with potassium permanganate give 3-(2-carboxyphenyl)-[l,2,4]triazole (121) (71CB3925). 

The acetates of acetamidine and benzamidine were condensed with 4-aminotriazole-S-carboxamide (73a) and its 7- and 8-methyl derivatives to give 2-metoyl- and 2-phenyl-8-azapurin-6-ones, respectively, in 80-90% yield, after refluxing for 4 - 8 h in butanol, hexanol, or octanol (toe choice of solvent determined toe optimal yield in each case). The reaction with tri-chlOFoacetamidine terminated at, e.g., (a-amino-i ) )9-trichloroethyliden-amino) 1,2,3-triazole (84) (from 73a). These intermediates were cyclized to 2-trichlorometoyl-8-azapurin-6-ones, in excellent yields, by stirring with 0.5 N potassium hydroxide (24°C, 5 h). This reaction gave only poor yields with 73b,c. 

When 4-amino-3-benzyl-l,2,3-triazole-5-carbonitrile was refluxed with ethanolic potassium hydroxide, the dimer 91a was isolated in 40% yield. A similar dimer (91b) was produced by the action of phenyl azide on malono-nitrile. ... 

The corresponding hydrochlorides do not react, so that the acetates seem to form a steady source of the more volatile and thermolabile bases. The course of the reaction is revealed by trichloroacetamidine, which takes the triazole no farther than an ethylideneamino derivative (153). This can be cyclized rapidly in cold 0.5 N potassium hydroxide to 2-trifluoromethyl-8-azapurin-6-one.248 Formamidine acetate has also been used to convert 2-aminopyrazine-3-carboxamide to pteridin-4-one in good yield.213... 

Grignard reagents RMgX into the amines RNH2 succeeds with the former but fails with the latter. The two reagents gave comparable yields in the iV-amination of pyridine and quinoline but for indole and carbazole the first was more effective. It was concluded that, in general, hydroxylamine-O-sulphonic acid was more versatile. 1,2,3-Triazole reacts with hydroxylamine 0-sulphonic acid in aqueous potassium hydroxide to yield a mixture of 53% 1-amino-l,2,3-triazole and 14% of the 2-amino isomer (equation 37) . ... 

Potassium hydroxide 2-Diazoindan-l,3-diones from o-cyano-co-diazoacetophenones via 8-oxoindeno[l,2-d]triazoles... 

Among (halkyl and diaryl (3-methylthio-l,2,4-triazol-5-yl)iminodithiocar-bonates prepared from 5-amino-1,2,4-triazoles, carbon disulfide, and an excess of potassium hydroxide with 2 mol equivalents of the corresponding alkyl or aralkyl hahdes, dimethyl (3-methylthio-l,2,4-triazole-5-yl)imino-dithiocarbamate 18 was isolated in both desmotropic forms. The form 18a crystaUized from hot acetonitrile, while the form 18b crystallized slowly from dilute ethanol. Both forms are stable enough in fresh -heptane and benzene-d solutions to give a possibility to differentiate them by UV and NMR (Scheme 12) (1990JHC1689). 

Adducts of thiocarbonohydrazides and carbodi-imides are also suitable precursors of 1,3,4-thiadiazoles. l-AW -Diarylamidino-S-phenylthiocar-bonohydrazides (86), arising from 1-phenylthiocarbonohydrazide (85) and diarylcarbodi-imides, are cyclized to the expected substituted 1,2,4-triazoles (87) by aqueous alkali, but yield 2-arylamino-5-phenylazo-l,3,4-thiadiazoles (89) on treatment with ethanolic potassium hydroxide. The observed formation of a 1,3,4-thiadiazole (89) in an alkaline medium conflicts with the general experience that linear compounds of general type (86) are cyclized to 1,2,4-triazoles in alkaline, and to 1,3,4-thiadiazoles in acidic media accordingly, the production of (91) could reasonably have been expected. 

Potassium hydroxide/alcohol 4-Hydroxy-l,2,3-triazoles from N-acylsydnone imines... 

In 2012, Song Cao et al. devised a novel, one-pot, three-component approach for the synthesis of 1,4,5-trisubstituted 1,2,3-triazoles 37 through the cycloaddition of a wide range of primary alcohols 36 with sodium azide and active methylene ketones 22 at 80 °C in the presence of Af-(p-toluenesulfonyl)imidazole (Tslm), tetrabutylammonium iodide (TBAl), and triethylamine (TEA) in DMF/DMSO (Scheme 4.12) [15]. Potassium hydroxide was used as the base for inducing the cycloaddition. The mild reaction conditions, high yields, and one-pot reaction without the necessity to isolate the unstable and hazardous... 

A number of general methods for the synthesis of meso-ionic 1,2,4-triazol-3-ones are available. Sodium ethoxide-catalyzed cyclization of 1-benzoyl-l,4-diphenylsemicarbazide (201, R = R = R = Ph, X = O) yielded anhydro-3-hydroxy-1,4,5-triphenyl-1,2,4-triazolium hydroxide (200, R = R = R = Ph). A general route to meso-ionic 1,2,4-triazol-3-ones (200) is exemplified by the formation of the 1,4,5-triphenyl derivative (200, R = R = R = Ph) from A-amino-MA -diphenylbenzamidine (202, R = R = R = Ph) and phosgene. In contrast with this ready meso-ionic compound formation, the corresponding reaction of the iV-methylbenzamidine (202, R = Me, R = R = Ph) did not yield the meso-ionic 1,2,4-triazol-3-one (200, R = Me, R = R = Ph). The product was in fact 3,4-diphenyl-2-methyl-l,2,4-triazol-5-onium chloride (203), which on heating gave 3,4-diphenyl-1,2,4-triazol-5-one (204, R = Ph). The formation of the A-methyl derivative (200, R = Me, R = R = Ph, yield 79%) by heating the 7V-thiobenzoyl semicarbazide (201, R = Me, R = R = Ph, X = S) with potassium carbonate in methyl cyanide has been reported. Another synthesis of A-methyl derivatives (200, R = Me) involves methylation of 3-methyl-4-phenyl-l,2,4-triazol-5-one (204,... 

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