methyl-phenyl-thioether; hydrogen fluoride; methoxybenzene; ortho-cresol 0.5 h; ice-bath;

1: TFA-anisole 2: HOBT-dicyclohexylcarbodiimide 3: TFA-anisole 4: HOBT-dicyclohexylcarbodiimide 5: TFA-anisole 6: HOBT, dicyclohexylcarbodiimide 7: HF, anisole-thioanisole-o-cresol / 0.5 h / ice bath View Scheme

1: t-Boc-L-valine With 4-methyl-morpholine; isobutyl chloroformate in tetrahydrofuran T=-10°C; 0.0833333 h; 2: L-Tyr-OBn With 4-methyl-morpholine; benzotriazol-1-ol in tetrahydrofuran; dichloromethane T=20°C; 3 h;

triethylamine in N,N-dimethyl-formamide T=20°C; Condensation; 24 h;

benzotriazol-1-ol; triethylamine; dicyclohexyl-carbodiimide 1) CHCl3, 0-5 deg C, 15 min, 2) CHCl3, 6 h; Yield given. Multistep reaction;