Scheme 1: Reaction conditions and reagents: (a) ethyl 2-chloroacetate, K2CO3, I2, acetone, reflux, 6 h; (b) DMSO, K2CO3, H2O, 85°C, 10 h; (c) 10% HCl, rt, overnight; (d) EDC, NHS, amines, DMF, rt, overnight; (e) 4 M HCl, EtOH, rt, overnight.