sodium carbonate in water 4 h; Ambient temperature;

thionyl chloride Heating;

1: N-[(1,1-dimethylethoxy)carbonyl]-L-histidine With benzotriazol-1-ol; dicyclohexyl-carbodiimide in N,N-dimethyl-formamide T=25°C; 2 h; 2: (S)-pyrrolidine-2-carboxamide in N,N-dimethyl-formamide T=25°C; 18 h;

sodium hydride in acetonitrile T=-15 - -5°C;

sodium hydride in acetonitrile T=-15 - -5°C;

1: 1-hydroxybenzotriazole, N-methylmorpholine, 1-ethyl-3-<(dimethylamino)propyl>carbodiimide hydrochloride / dimethylformamide / 1.) -23 deg C, 2 h, 2.) RT, 16 h 2: ethanolic HCl / 1 h 3: 1-hydroxybenzotriazole, N-methylmorpholine, 1-ethyl-3-<(dimethylamino)propyl>carbodiimide hydrochloride / dimethylformamide / 1.) -23 deg C, 2 h, 2.) RT, 16 h View Scheme

sodium hydride in acetonitrile T=-15 - -5°C;