Sodium ethoxide → HCID 68515561、化合物

Ethyl 5-methyl-3-oxo-4-hexenoate (1.10 g, 6.56 mmol, 1.1 eq.) obtained in Example 95a) and 4-azido-N-ethylbenzamide (purity 90%, 1.23 g, 5.82 mmol) were dissolved in ethanol (25 ml), sodium ethoxide (550 mg, 7.82 mmol, 1.25 eq.) was added, and the mixture was stirred at room temperature for 30 min and at 50° C. for 10.5 hr. Ethanol was evaporated from the reaction mixture, and the residue was diluted with 2% aqueous sodium carbonate solution (40 ml) and washed with ethyl acetate (40 ml). The organic layer was extracted with 2% aqueous sodium carbonate solution (15 ml). The aqueous layers were combined, washed with ethyl acetate-hexane (2:1, 50 ml), acidified (pH<3) with 6N hydrochloric acid and extracted three times with ethyl acetate (50 ml) and ethyl acetate-THF (3:1, 40 ml). The organic layers were combined, washed with saturated brine, dried over anhydrous sodium sulfate and concentrated, and ethyl acetate was added. The precipitate was collected by filtration, washed with ethyl acetate and diethyl ether and dried to give the title compound as a grayish white powder (1.43 g, 4.55 mmol, 78.2%).