1: 1-(3,4-dichloro-phenyl)-3-aza-bicyclo[3.1.0]hexane-2,4-dione With sodium hydride in N,N-dimethyl-formamide T=0 - 20°C; 1.5 h; Cooling with ice/salt/water bath; 2: propyl bromide in N,N-dimethyl-formamide T=20°C;

sodium acetate in acetic anhydride 4 h; Heating / reflux;