Sodium Hydroxide → 7-Chloro[1,2,4]triazolo[1,5-a]pyrimidine

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Reaction Steps

5.4 g of [1,2,4]triazolo[1,5-a]pyrimidin-7-ol from the first synthesis step are introduced into 20 ml of phosphorus oxychloride with vigorous stirring. After completion, the mixture is warmed under reflux for a further 1.5 h. For work-up, the cooled batch is stirred in portions into 100 ml of ice-water and subsequently adjusted to pH 12 using conc. NaOH solution. The aqueous phase is extracted with ethyl acetate. The combined organic phases are dried over sodium sulfate, and the solvent is removed in vacuo. The 7-chloro-[1,2,4]triazolo[1,5-a]pyrimidine obtained is employed in the following reaction without further purification; m.p. 190° [lit. 186-187° C.];

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