Hydrogen chloride-ethyl acetate → N-((2S)-1-((2-(4-(cyclopropylmethoxy)-3,5-difluorophenyl)-1,3-benzoxazol-6-yl)oxy)propan-2-yl)acetamide
Reaction equation
[CH:1]1([CH2:4][O:5][C:6]2[C:11]([F:12])=[CH:10][C:9]([C:13]3[O:14][C:15]4[CH:21]=[C:20]([O:22][CH2:23][C@@H:24]([NH:26][C:27](=O)[O:28]C(C)(C)C)[CH3:25])[CH:19]=[CH:18][C:16]=4[N:17]=3)=[CH:8][C:7]=2[F:34])[CH2:3][CH2:2]1.Cl.[C:36](OCC)(=O)C>>[CH:1]1([CH2:4][O:5][C:6]2[C:7]([F:34])=[CH:8][C:9]([C:13]3[O:14][C:15]4[CH:21]=[C:20]([O:22][CH2:23][C@@H:24]([NH:26][C:27](=[O:28])[CH3:36])[CH3:25])[CH:19]=[CH:18][C:16]=4[N:17]=3)=[CH:10][C:11]=2[F:12])[CH2:2][CH2:3]1Participants
3
Procedure
To tert-butyl ((2S)-1-((2-(4-(cyclopropylmethoxy)-3,5-difluorophenyl)-1,3-benzoxazol-6-yl)oxy)propan-2-yl)carbamate (2.60 g) was added 4 M hydrogen chloride/ethyl acetate (10 mL), and the mixture was stirred at room temperature for 10 min, and concentrated. To the residue were added pyridine (10 mL) and acetic anhydride (10 mL), and the mixture was stirred at room temperature for 15 min. The reaction mixture was concentrated under reduced pressure, and the residue was dissolved in ethyl acetate/methanol, and the solution was subjected to silica gel column chromatography (NH, ethyl acetate). The solvent was evaporated, and the obtained solid was washed with diethyl ether to give the title compound (1.39 g).