1: 1-(tert-butoxycarbonyl)-L-proline With thionyl chloride; N,N-dimethyl-formamide in toluene T=5°C; 2 h; Cooling with ice; 2: 4-chloro-aniline in toluene T=20°C; 12 h;

trifluoroacetic acid in dichloromethane 1 h;