反应详情

(2R,4S)-4-{[3,5-Bis(trifluoromethyl)benzyl]-[5-(N-hydroxy-carbamimidoyl)pyridin-2-yl]}amino-2-ethyl-6-methoxy-3,4-dihydro-2H-[1,5]naphthyridine-1-carboxylic acid ethyl ester (193 mg) and triethylamine (126 μl) are dissolved in dichloromethane (3 ml), and thereto is added triphosgene (268 mg) at 0° C. The mixture is stirred at room temperature for 30 minutes. To the reaction solution are added water and dichloromethane, and the organic layer is washed with saturated brine. Then the organic layer is dried over sodium sulfate, and then concentrated under reduced pressure. The resulting residue is purified by column chromatography (silica gel; chloroform:methanol=1:0→97:3) to give (2R,4S)-4-{[3,5-bis(trifluoromethyl)benzyl]-[5-(5-oxo-4,5-dihydro-[1,2,4]oxadiazol-3-yl)pyridin-2-yl]}amino-2-ethyl-6-methoxy-3,4-dihydro-2H-[1,5]naphthyridine-1-carboxylic acid ethyl ester (33 mg). MS (m/z): 667 [M+H]+.

1. washthe organic layer is washed with saturated brine
2. dry with materialThen the organic layer is dried over sodium sulfate
3. concentrationconcentrated under reduced pressure
4. customThe resulting residue is purified by column chromatography (silica gel; chloroform:methanol=1:0→97:3)