Sodium hydride → Diethyl 2-(tert-butoxyformamido)-2-[(5-oxazolyl)methyl]malonate

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反応条件

反応手順

301 mg of a 60% dispersion of sodium hydride in mineral oil were added portionwise to 60 ml of anhydrous ethanol at 0° C. and the resulting suspension was stirred at 0° C. for 5 minutes. 1.88 g of diethyl 2-(tert-butoxyformamido)malonate were added and the mixture was warmed to room temperature. After stirring at room temperature for 10 minutes 805 mg of 5-(chloromethyl)oxazole were added. The mixture was stirred at room temperature for 30 minutes and at 60° C. for 1 hour. The solvent was evaporated and the crude product was dissolved in diethyl ether and washed with water. Sodium chloride was added to the aqueous layer, which was then extracted with diethyl ether. The combined organic layers were dried over magnesium sulphate and the solvent was removed by evaporation. Purification of the residue by chromatography on silica gel using ethyl acetate/hexane (1:2) for the elution gave diethyl 2-(tert-butoxyformamido)-2-[(5-oxazolyl)methyl]malonate, 1H NMR (250 MHz, CDCl3) δ: 1.3 (t,6H), 1.45 (s,9H), 3.75 (s,2H), 4.2 (m,4H), 5.85 (s,1H), 6.8 (s,1H), 7.75 (s,1H).

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