1.2.4- Triazoles thiosemicarbazides

Triazole-3(5)-thiol has been prepared by heating thio-semicarbazide and formic acid, by heating l-formyl-3-thiosemi-carbazide, and by heating 1,3,5-triazine and thiosemicarbazide. The ring closure of l-formyl-3-thiosemicarbazide using aqueous base was suggested by L. F. Audrieth and F. Hersman. 

Thionyl fluoride, as by-product in sulfur tetrafluoride reactions, 41, 105 toxidty of, 41,105 Thiophene-2-OL, 43, 55 2(5H)-Thiophenone, 43, 55 Thiosemicarbazide, in synthesis of 1,2,4 triazole, 40, 99 reaction with formic acid to yield l-formyl-3-thiosemicarbazide, 40,99... 

Formaldehyde hydrazones react with N,AT -thiocarbonyldi-1,2,-4-triazole to give hydra-zones of thioglyoxalyl-1,2,4-triazoles, which react readily under displacement of 1,2,4-triazole with nucleophilic reagents such as amines and hydrazines but also with less nucleophilic compounds, including hydrazones, sulfonylhydrazides, thiosemicarbazides, and hydrazides.[10]... 

Triazole. RingschluB zu 1.2.4-Triazolderivaten (XLIII) er-folgt, wenn s-Triazin auf Verbindungen vom Typ des Semicarbazids, Thiosemicarbazids und Aminoguanidins einwirkt (24). 

Acylation of thiosemicarbazides with acyl chloride 222, under standard basic conditions, gives 2-aryl-5-methyl-thia-zolo[3.2-// [ l, 2,4]triazolc-6-carbothiosemicarbazides 223, that on sodium hydroxide-promoted cyclization affords 2-aryl-5-methyl-thiazolo[3,2-4][l,2,4]triazol-6-yl)-l//-l,2,4-triazole-3-thiones224 (unreported yields) (Scheme 14) <2001FAR15>. 

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>. 

Jain and Handa reported [82IJC(B)732] that the mode of ring closure may depend critically on the 5-substituent of the triazole. 3-Mercapto-5-(4 -pyridyl)[l,2,4]triazole 143 was reacted with phenacyl bromides to give 144, which on treatment with PPA resulted in the formation of thiazolo[2,3-c][l,3,4]triazoles 145. The structure of 145 [R = (4-Cl)C6H4] was proved by an independent synthesis starting with isonicotinyl thiosemicarbazide. 

The thiosemicarbazide (147) cyclises to the triazole (148) on treatment with sodium hydroxide (Equation (55)) <92BAU534> and (149) undergoes a similar reaction to give (150) (Equation (56)) <90JOU737>. 

Ph) is transformed by reaction with aniline into the l,2,4-triazole-3-thione (161, R = Me, = Ph) the presumption that this transformation involves the thiosemicarbazide 160b as an intermediate is supported by the isolation of the derivative 160c by a similar reaction with diethylaraine. ... 

Reaction of 232 with 4-substituted l,3-oxazol-5(4/7)-one 247 led to diacylhydrazines 248 or to imidazole derivatives 249 depending on the reaction temperature (Scheme 24). l,2,4-Triazole-3-thione 250 was obtained by a two-step sequence from 232 with phenyl isothiocyanate and subsequent base-catalyzed cyclization of thiosemicarbazide 251. The effects of hydrazones 241-246 on inhibition of photosynthetic electron transport in spinach chloroplasts and chlorophyll content in the antialgal suspensions of Chlorella vulgaris were investigated <2005CEC622>. 

The 1,2,4-triazole ring of 2,3,5,6,7,8-hexahydro-l,2,4-triazolo[4,3-a] pyrimidin-3-ones (60) was constructed by cyclocondensation of the 1-ethoxycarbonyl-2-methylthio-l,4,5,6-tetrahydropyrimidine 58 with hydrazine (86JPR331), arylhydrazines [86H(24)93, 86KGS1350 88JPR753], or thiosemicarbazide (87KGS1540) (Scheme 24). 

Some new 5-(benzylamino)thiatriazoles have been prepared by standard methods.12 5-(Tetra-0-acetyl-/T-D-glucopyranosylamino)-thia-triazole was prepared by the action of HN02 on 4-(tetra-0-acetyl-/3-D-glucopyranosyl)thiosemicarbazide as well as from hydrogen azide and tetra-0-acetyl-/J-D glucopyranosyl isothiocyanate.62 Substituted 5-aminothiatriazoles may be obtained from C-sulfonylthioformamides on reaction with azide ion.63... 

Treatment of aromatic carboxaldehyde (diaminomethylene)hydrazones (105) with hot acetic anhydride or benzoyl chloride affords l,4-diacyl-3-acylamino-5-ary 1-4,5-dihydro- 1H-1,2,4-traizoles (106) in 75-95% yields. In contrast, when the 4-pyridine analog of 105 was employed, the unusual hemianimal triazole derivative (107) was obtained. The structures of the novel compounds were determined by spectral methods and in several cases by x-ray structural analysis. Mechanistic considerations are discussed [95M733]. The oxazole-1,2,4-triazole (108) was prepared by cyclization of the corresponding oxazolecarbonyl-thiosemicarbazide with bicarbonate, alkylation at the sulfur and oxidation to the sulfoxide with MCPBA [95JHC1235]. 

The reaction of oxalyl hydrazide with aryl isothiocyanate gives the bis(thiosemicarbazide) (162) which under acidic conditions cyclizes to the bis(l,3,4-thiadiazole) (163). Under alkaline conditions the 5-mercapto-l,2,4-triazole (164) is obtained (77BSB399). 

BHC see Lindane Bifenox phenyl ether Bifenthrin pyrethroid Binapacryl dinitrophenol derivate Bioresmethrin pyrethroid Bisthiosemi (other) thiosemicarbazide Bitertanol heterocyclic nitrogen, triazole Brodifacoum coumarin... 

Various 3,5-disubstituted 1,2,4-triazoles 593 have been prepared in good yields by the reaction of nitriles 591 with acylhydrazides 592 in the presence of catalytic potassium carbonate under microwave heating (Scheme 266) <2005TL3429, CHEC-III(5.02.9.2)182>. Likewise, alkyl and aryl nitriles 594 react with thiosemicarbazide 595 under acidic conditions to give 1,3,4-thiadiazoles 596 (Scheme 267) <1995BML1995, CHEC-III(5.10.9.2.2)595>. 

By analogy with what is known for thiosemicarbazide, cyclizations of thiocarbohydrazide (47) could be expected to lead to hydrazino-thiadiazoles. However, a much stronger tendency toward formation of triazoles is apparent in the latter case, and thiadiazoles are formed only in special reactions. Thus 1-thiocarbamoylthiocarbohydrazide... 

A series of fluorine-containing triazole (i) have been synthesized by the treatment of thiosemicarbazides with 1% NaOH by green techniques [13]. 

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