1,1'-Carbonyldiimidazole → Ethyl 2-amino-2-(4-trifluormethyl-3-pyridinecarbonyloxyimino)-acetate

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Reaction Steps

17.3 g of carbonyidiimidazole are initially charged in 200 ml of 1,4-dioxane and, a little at a time, admixed with 20 g of 4-trifluoromethyl-3-pyridinecarboxylic acid. The mixture is stirred at room temperature for 1 h and subsequently heated to 45° C. for 2 h. After cooling to 30° C., 14.5 g of ethoxycarbonylformamide oxime are added and the mixture is stirred at 45° C. for 3 h. The precipitated solid is filtered off with suction and the filtrate is concentrated to 50 ml and, together with the solid, added to 250 ml of ice-water. The solid is filtered off with suction and dried at 50° C. under reduced pressure. This gives 28.7 g of the product as a white solid of mp. 172-174° C.

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