Isatoic Anhydride → 2-amino-N'-(4-chlorophenyl)benzohydrazide

Participants

Reaction Steps

4-Chlorophenylhydrazine hydrochloride (2.105 g, 14.76 mmol) was suspended in EtOH (25 ml), treated with di-isopropylethylamine (2.253 ml, 12.93 mmol) and stirred for 30 minutes. Isatoic anhydride (1.918 g, 11.76 mmol) was added and the mixture was heated to reflux for 3 hours. The reaction mixture was cooled to room temperature and stirred overnight. The material was concentrated to dryness and the resulting residue was partitioned between EtOAc (˜25 ml) and 50% saturated NaCl (3×30 ml). The organic layer (also containing a small amount of emulsion which would not dissipate over 3 extractions) was dried over MgSO4 and concentrated to an orange solid. The material was triturated with EtOAc, filtered and rinsed with additional EtOAc. The filtrate was concentrated to dryness and treated with DCM (dichloromethane). The mixture was stirred overnight. The mixture was filtered, rinsed with DCM and the solid dried to provide 1.538 g (50%) of 2-amino-benzoic acid N′-(4-chloro-phenyl)-hydrazide (Intermediate 40) as a mauve-colored solid. MS (APCI): (M+1)=262.1, (M−1)=260.0.

Provenance & Evidence