4-(N,N-dimethlyamino)pyridine; amberlyst-15; 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide on Merrifield's resin 1.) ClCH2CH2Cl, t-BuOH, rt., 24 h; 2.) EtOAc, 2 h; Yield given. Multistep reaction;