Benzoic acid, 4-[(2E)-2-buten-1-yloxy]- → Tert-butyl 2-({4-[(2e)-but-2-en-1-yloxy]benzoyl}amino)-3-[4-(trifluoromethoxy)phenyl]propanoate

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Reaction Steps

4-(4,6-Dimethoxy-1,3,5-triazin-2-yl)-4-methylmorphorinium chloride (DMT-MM, 332 mg, 1.20 mmol) was added to a methanol (6 mL) solution of tert-butyl 2-amino-3-[4-(trifluoromethoxy)phenyl]propanoate (305 mg, 1.00 mmol) and 4-[(2E)-buten-2-yloxy]benzoic acid (192 mg, 1.00 mmol) prepared in Example 32 (32a). The mixture was stirred at room temperature for 4 hours and 50 minutes. The solvent was evaporated, and the residue was purified by silica gel column chromatography (n-hexane:ethyl acetate, 19:1 and 4:1, V/V) to give 421 mg of tert-butyl 2-({4-[(2E)-but-2-en-1-yloxy]benzoyl}amino)-3-[4-(trifluoromethoxy)phenyl]propanoate (colorless oil). This oily compound (492 mg, 1.03 mmol) was dissolved in methylene chloride (20 mL), and trifluoroacetic acid (4 mL) was added thereto at room temperature. The resulting mixture was stirred at the same temperature for 4.5 hours. The solvent was evaporated, and the residue was suspended in diisopropyl ether. The insoluble substance was collected by filtration, washed with diisopropyl ether, and dried to give 284 mg of the title compound (white powder, yield: 57%).

Provenance & Evidence