1: With benzoyl isocyanate in dichloromethane T=55°C; 1 h; 2: With sodium methylate in methanol 2 h; Reflux;

1.1: potassium carbonate / dimethyl sulfoxide / 4 h / 80 °C 2.1: 3-chloro-benzenecarboperoxoic acid / chloroform / 4 h / 20 °C 3.1: benzoyl isocyanate / dichloromethane / 1 h / 55 °C 3.2: 2 h / |Reflux View Scheme

1.1: 3-chloro-benzenecarboperoxoic acid / chloroform / 4 h / 20 °C 2.1: benzoyl isocyanate / dichloromethane / 1 h / 55 °C 2.2: 2 h / |Reflux View Scheme