1: oxalyl chloride / benzene; dimethylformamide / 0.5 h 2: triethylamine, 4-(dimethylamino)pyridine / tetrahydrofuran / 2 h / Ambient temperature View Scheme

4-(N,N-dimethlyamino)pyridine; triethylamine in tetrahydrofuran 2 h; Ambient temperature; Yield given;