1: 2-(2,5-dioxo-2,5-dihydro-1H-pyrrol-1-yl)benzoic acid With oxalyl dichloride; N,N-dimethyl-formamide T=20°C; 1 h; 2: triethyl phosphite in dichloromethane T=40°C; 2 h; 3: in acetonitrile 2 h; Reflux;

1: 2-(2,5-dioxo-2,5-dihydro-1H-pyrrol-1-yl)benzoic acid With oxalyl dichloride; N,N-dimethyl-formamide T=20°C; 1 h; 2: triethyl phosphite in dichloromethane T=40°C; 2 h;

sodium acetate; acetic anhydride T=75°C; 0.166667 h;

acetic acid T=120 - 125°C; 16 h;