1: 89 percent / 4 N HCl / acetic acid / 0.5 h 2: 1.) triethylamine (TEA), 2.) N-hydroxybenzotriazole (HOBt), N,N'-dicyclohexylcarbodiimide (DCC) / 1.) DMF, 23 deg C, 0.5 h, 2.) DMF a.) 0 deg C, 2 h, b.) 23 deg C, 15 h View Scheme

Multi-step reaction with 2 steps 1: 4 N HCl / ethyl acetate2: 1.) triethylamine (TEA), 2.) N-hydroxybenzotriazole (HOBt), N,N'-dicyclohexylcarbodiimide (DCC) / 1.) DMF, 23 deg C, 0.5 h, 2.) DMF a.) 0 deg C, 2 h, b.) 23 deg C, 15 h  

Multi-step reaction with 2 steps 1: 89 percent / 4 N HCl / acetic acid / 0.5 h2: 1.) triethylamine (TEA), 2.) N-hydroxybenzotriazole (HOBt), N,N'-dicyclohexylcarbodiimide (DCC) / 1.) DMF, 23 deg C, 0.5 h, 2.) DMF a.) 0 deg C, 2 h, b.) 23 deg C, 15 h