Trifluoroacetic acid → 1-((3-(3-Phenyl-4-(trifluoromethyl)isoxazol-5-yl)-4,5-dihydronaphtho[1,2-c]isoxazol-7-yl)methyl)azetidine-3-carboxylic acid

Participants

Reaction Steps

To a stirred solution of tert-butyl 1-((3-(3-phenyl-4-(trifluoromethyl)isoxazol-5-yl)-4,5-dihydronaphtho[1,2-c]isoxazol-7-yl)methyl)azetidine-3-carboxylate (7C, 2.24 g, 4.06 mmol) in dichloromethane (4 mL) was added TFA (4 mL) slowly at room temperature. The reaction mixture was stirred at room temperature for 2 hr. The mixture was concentrated to remove dichloromethane and TFA (6 mL) was added. The mixture was stirred at room temperature till the starting material was observed to disappear. Dichloroethane (6 mL) was added and the mixture was concentrated under reduced pressure. The residue was mixed with water (10 mL), basified with 1 N aqueous NaOH to pH=8 and acidified with 1N aqueous HCl to pH=5. The mixture was sonicated for 30 min. The solid was filtered and washed with water (4×10 mL). The wet solid was mixed with methanol (40 mL), sonicated for 30 min, filtered, washed with methanol (3×10 mL), and dried to give 1-((3-(3-phenyl-4-(trifluoromethyl)isoxazol-5-yl)-4,5-dihydronaphtho[1,2-c]isoxazol-7-yl)methyl)azetidine-3-carboxylic acid as a white solid.

Provenance & Evidence