Pyridine → 1,1-dimethylethyl 3-(1,2,4-thiadiazol-5-yl)-5,6-dihydro[1,2,4]triazolo[4,3-a]pyrazine-7(8H)-carboxylate

Participants

Reaction Conditions

Reaction Steps

A mixture of 1,1-dimethylethyl 3-({[(1E)-(dimethylamino)methylidene]amino}carbonothioyl)-5,6-dihydro[1,2,4]triazolo[4,3-a]pyrazine-7(8H)-carboxylate (I113)(0.118 g, 0.349 mmol) and pyridine (0.056 ml, 0.698 mmol) in ethanol (2 ml) was stirred at 25° C. and hydroxylamine O-sulfonic acid (0.043 g, 0.384 mmol) in methanol (1.2 ml) was added in one batch. The mixture was stirred at RT and after a few minutes the solution became clear. After 1 h, the mixture had changed from orange to pale yellow in colour. The solvents were evaporated and the concentrated mixture was diluted with DCM (50 ml) and washed with water (5 ml), 0.2M NaOH (5 ml) and water (5 ml) and the organic layer was dried and concentrated. Chromatography (SP4, 0-100% ethyl acetate in isohexane) gave a white foam (58 mg). NMR showed some high field impurities therefore the foam was triturated with isohexane to give a white solid in 51.2 mg of desired product.

Provenance & Evidence