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Reactions of 1,2,4-triazole derivatives with a “model” thiirane

“…The products of reaction at the position N 4 were not mentioned in [3,4]. We also did not found a product of the reaction at the position N 4 in treating with thiirane I the unsubstituted 1,2,4-triazole [2].…”

“…We investigated the reactions of 3-mono-and 3,5-disubstituted 1,2,4-triazoles with thiiranes by an example of a "model" thiirane suggested by us [2], 8-bromo-1,3-dimethyl-7-(thiiran-2-ylmethyl)-3,7-dihydro-1H-purine-2,6-dione (I), whose application made it possible to obtain monomer products in reactions with nucleophiles owing to the intramolecular heterocyclization affording derivatives of 6,7-dihydro [1,3]thiazolo[2,3-f]purine-2,4(1H,3H)-dione (Scheme 1).…”

“…The reaction of 3-nitro-1,2,4-triazole with oxiranes is known to proceed at the position N 1 of the triazole [3], whereas the 3-azido-1,2,4-triazole gave with oxiranes a mixture of reaction products at positions N 1 and N 2 [4]. The products of reaction at the position N 4 were not mentioned in [3,4].…”

“…The reaction of symmetric 3,5-dibromo-1H-1,2,4-triazole (IIa) with thiirane I led to the formation of 7-[(3,5-dibromo-1H-1,2,4-triazol-1-yl)methyl]-1,3-dimethyl-6,7-dihydro [1,3]-thiazolo[2,3-f]purine-2,4(1H,3H)-dione (III) (Scheme 2) in 77% yield. 1 H NMR spectrum of compound III confirmed the formation of the fused system of the dihydrothiazolopurine: characteristic multiplets appeared in the regions 4.62-4.74 and 4.96-5.06 ppm, corresponding to the protons of NCH 2 and SCH groups of the dihydrothiazole ring respectively [5,6].…”

“…The reaction of thiirane I with unsymmetrical 3-methylsulfonyl-1H-1,2,4-triazole (IIb) proceeded regiospecifically at the position N 1 of the triazole ring (Scheme 2). 1,3-Dimethyl-7-[(3-methylsulfonyl-1H-1,2,4-triazol-1-yl)methyl]-6,7-dihydro [1,3]…”