N1C=CC=CC=1.[FH:7].[O:8]1[C:10]2([CH2:15][CH2:14][N:13]([C:16]([O:18][CH2:19][C:20]3[CH:25]=[CH:24][CH:23]=[CH:22][CH:21]=3)=[O:17])[CH2:12][CH2:11]2)[CH2:9]1.C(=O)(O)[O-].[Na+]>C(Cl)Cl>[F:7][C:10]1([CH2:9][OH:8])[CH2:15][CH2:14][N:13]([C:16]([O:18][CH2:19][C:20]2[CH:25]=[CH:24][CH:23]=[CH:22][CH:21]=2)=[O:17])[CH2:12][CH2:11]1A mixture of 5 ml hydrogen fluoride pyridine and 20 ml methylene chloride was cooled, and 10 ml solution of 4.95 g of benzyl 1-oxa-6-azaspiro[2.5]octane-6-carboxylate in methylene chloride was added dropwise thereinto over 25 min such that the bulk temperature was 0° C. or less. The mixture was stirred for 35 min under ice-cooling. The reaction solution was poured into a mixture of saturated sodium bicarbonate and ice. The organic layer was recovered, dried over anhydrous magnesium sulfate, and filtered. The filtrate was evaporated, and then subjected to silica gel column chromatography to give 2.84 g of the title compound.
Loading…
