Hydrochloric Acid → 2-(6-Chloropyrimidin-4-yl)-4-(1H-1,2,3-triazol-1-yl)-1,2-dihydro-3H-pyrazol-3-one hydrochloride

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Reaction Steps

10.0 g (47.7 mmol) of the compound from Example 3A and 8.3 g (57.1 mmol) of the compound from Example 7A are initially introduced into 100 ml ethanol and 1.5 ml (2.2 g, 19.0 mmol) TFA are added. The mixture is stirred under reflux for 12 h. A 4 M solution of hydrogen chloride in dioxane is then added in excess to the cooled reaction mixture, the mixture is extracted by stirring for approx. 1 h, the crystals which have precipitated out are filtered off and the residue on the filter is washed with dioxane and ethanol. The intermediate product obtained in this way is dissolved in 150 ml ethanol, 50 ml of a 25% strength methanolic sodium methylate solution are added and the mixture is stirred at RT for 2 h. The reaction mixture is then adjusted to pH 5 with 1 N hydrochloric acid and extracted by stirring at RT for a further 2 h, the solid is filtered off, the residue on the filter is washed with ethanol and the product is dried in vacuo.

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