General procedure for the synthesis of 5-chloro-3-phenylbenzo[c]isoxazoles from 2-amino-5-chlorobenzophenone: Oxone (0.270 g, 0.44 mmol) was added to (E)-1-(2-aminophenyl)-3-(4-fluorophenyl)prop-2-en-1-one (1 g, 0.44 mmol) in a MeCN/H?O (2.5 mL/2.5 mL) solution. The reaction mixture was stirred at room temperature and the reaction progress was monitored by TLC and GC-MS. After stirring for 24 h, H?O (150 mL) and CH?Cl? (150 mL) were added for extraction. The organic layer was separated and the aqueous layer was further extracted with CH?Cl? The combined organic layers were washed with H?O, dried over anhydrous Na?SO?, filtered and concentrated. Purification by silica gel column chromatography (n-hexane/EtOAc, 98:2) afforded 3 g of the target product 2,1-benzisoxazole.
