Synthesis of symmetrical di(pyrimidin-2-yl)-1,2,4-triazoles and di(pyrimidin-2-yl)-1,2,4,5-tetrazines

Abstract

The reactions of pyrimidine 2 carbonitrile and 4,6 dimethylpyrimidine 2 carbonitrile with hydrazine hydrate were investigated. Intermediates in the route of successive transformations of pyrimidine 2 carbonitrile (pyrimidine 2 carbamidrazone and 1,2 bis[amino(pyrimidin 2 yl)methylidene]hydrazine) into trinuclear heterocyclic compounds, viz., symmetrical di(pyrimidin 2 yl) 1,4 dihydro 1,2,4,5 tetrazines and di(pyrimidin 2 yl) 4H 1,2,4 triazol 4 amines (potential polydentate ligands), were isolated. The oxidative dehydrogenation of di(pyrimidin 2 yl) 1,4 dihydro 1,2,4,5 tetrazines afforded the corresponding 3,6 di(pyrimidin 2 yl) 1,2,4,5 tetrazines.Key words: pyrimidine 2 carbonitrile, 4,6 dimethylpyrimidine 2 carbonitrile, pyrimidine 2 carbamidrazone, 3,6 di(pyrimidin 2 yl) 1,4 dihydro 1,2,4,5 tetrazines, 3,6 di(pyrimidin 2 yl) 1,2,4,5 tetrazines, 3,5 di(pyrimidin 2 yl) 1H 1,2,4 triazole, 3,5 di(pyrimidin 2 yl) 4H 1,2,4 triazol 4 amines. Substituted 1H and 4H 1,2,4 triazoles exhibit prop erties of metal corrosion inhibitors. 1 These compounds are used also as ligands for the synthesis of transition metal complexes, being coordinated to metal ions through the N(1),N(2) or N(2),N(4) atoms of the triazole ring to form oligo or polynuclear complexes. 2 Transition metal com plexes with triazoles can exhibit ferro or antiferromag netic exchange interactions. 3,4 For the Fe II complexes, the spin transition 1 A 1 ⇔ 5 T 2 and the thermochromism can be observed. 5-7 4H 1,2,4 Triazol 4 amines, unlike par ent 1H 1,2,4 triazole, are usually coordinated to metal atoms as bidentate bridging ligands through the N(1) and N(2) atoms of the triazole ring. 2

A Facile Environ-friendly One-pot Water-promoted Synthesis of Bis 1,2,3-triazole Linked Bis 2 - Aminopyrimidine Hybrids

“…In the present investigation, an elegant and e cient synthesis of a series of novel (1,4) bis 1,2,3-triazole fused aminopyrimidine derivatives has been achieved and reported for the rst time in green solvent viz water. The chromatographic separation is not required in our method as the pure product is thrown out in the water medium.…”

“…Triazole, tetrazole, oxazole, imidazole and pyrazole are receiving much more attention due to their potential biological activities. A lot of fused heterocyclic ring owning pyrimidinepyrazole 4 , benzoxazole 5 , benzimidazole, pyrimidotriazipine 6 , have been described as e cient pharmacophores. Among the overhead, pyrimidine based fused pharmacophore 7,8,9 plays a vital role for numerous biological activities such as analgesic 10 , anticonvulsant 11 , antiparkinsonian 12 , Anti bacterial 13,14 , anti-microbial 15 .…”

The inverse-electron demand Diels–Alder reaction of tetrazines with cyclic enol ethers

“…All reagents were used without further purification unless otherwise noted. Tetrazines 1a, 1b, and 1c were prepared according to literature [33][34][35]. NMR spectra were recorded on a Bruker Avance III 300 MHz FT NMR spectrometer (300.36 MHz ( 1 H), 75.53 MHz ( 13 C)).…”

The synthesis of 4-amino -5-(pyridin-2(3)-Yl) -1,2,4-triazole (4H)-3-ylthio acetamide derivatives as potential anti-inflammatory substances

“…Результати дослідження та їх обговорення На даний момент існує декілька основних спо-собів одержання похідних 4-аміно-3-меркапто-1,2,4-триазолу: класичною методикою є взаємодія карбо-нових кислот [19,20] або їх естерів [21] з дигідрази-нокарботіоном; для синтезу 5-арил/гетерилзаміщених похідних застосовується взаємодія гідразидів карбо-нових кислот через стадію одержання відповідних калій гідразинокарбодитіоатів з наступною конден-сацією з гідразин гідратом [22,23]; зазначені похідні утворюються і при обробці заміщених 1,3,4-окса-діазол-2-тіонів надлишком гідразин гідрату [23].…”