[C:1](N1C=CN=C1)(N1C=CN=C1)=[O:2].[NH2:13][C:14]1[C:19]([F:20])=[CH:18][CH:17]=[CH:16][C:15]=1[OH:21]>C1COCC1.C(OCC)(=O)C>[F:20][C:19]1[C:14]2[NH:13][C:1](=[O:2])[O:21][C:15]=2[CH:16]=[CH:17][CH:18]=11,1′-Carbonyldiimidazole (11.4 g, 0.0703 mol) is added portionwise to a solution of 2-amino-3-fluorophenol (Step 3, 8.94 g, 0.0703 mol) in THF (200 ml) and warmed at 60° C. for 2 h. The reaction mixture is diluted with ethyl acetate (200 ml), washed with 2N HCl and saline, dried (MgSO4), and evaporated to give product as a white solid suitable for use in the next step (10.6 g, 99%); mp 131–3° C.
불러오는 중…