1: Boc-Ala-MBHA resin With trifluoroacetic acid in dichloromethane T=20°C; 1 h; 2: phenyl isocyanate in tetrahydrofuran T=60°C; 0.166667 h; microwave irradiation; 3: With triethylamine in tetrahydrofuran; N,N-dimethyl-formamide T=110°C; 0.25 h; microwave irradiation; Further stages.;

hydrogenchloride

sodium methylate in methanol

sodium hydroxide in ethanol 2 h;

hydrogenchloride; potassium hydroxide 1.) room temp., 24 h, 2.) reflux, 1 h; Yield given. Multistep reaction;

1: aq. KOH 2: NaNO2 / formic acid 3: H2O View Scheme