Reagents and conditions: (a) 2-methoxbenzoyl chloride, DIEA, DCE, room temperature; (b) 2,4-dichlorobenzoyl chloride, DIEA, DCE, room tempera- ture; (c) 4-morpholinecarbonyl chloride, DIEA, DCE, room temperature; (d) phenylsulfonyl chloride, DIEA, DCE, room temperature.