4-Methylmorpholine → 2-amino-6-fluoro-benzoic acid N'-(2-fluoro-phenyl)-hydrazide

Participants

Reaction Conditions

Reaction Steps

2-Amino-6-fluorobenzoic acid (2.00 g, 12.89 mmol) was combined with 2-fluorophenylhydrazine hydrochloride (2.096 g, 12.89 mmol) and HOBt (3.949 g, 25.79 mmol) in dry THF (75 ml) and cooled to about −12° C. N-Methylmorpholine (2.835 ml, 25.79 mmol) was added, the mixture was stirred for 5 minutes, then EDC hydrochloride (2.66 g, 13.88 mmol) was added. The mixture was maintained at a temperature between −14 and −10° C. for 1 hour, then allowed to slowly warm to room temperature and stirred for 18 hours. The mixture was cooled to 0° C., then filtered through CELITE® (diatomaceous earth). The filtrate was diluted with EtOAc, treated with saturated NaHCO3 and the layers separated. The organic layer was washed twice with 50% saturated NaHCO3 and then dried over MgSO4 and concentrated. The resulting solid was triturated with dichloromethane, filtered, rinsed with a very small amount of dichloromethane and dried. The filtrate from the trituration was re-triturated with a small amount of dichloromethane, filtered, rinsed with a tiny amount of dichloromethane and dried. The filtrate was concentrated to dryness, triturated with a small amount of Et2O, filtered, rinsed with a tiny amount of ether and dried. The three solids were combined to afford a total of 2.182 g (64%) of 2-amino-6-fluoro-benzoic acid N′-(2-fluoro-phenyl)-hydrazide (Intermediate 44) as an off-white solid. MS (APCI): (M−1)=262.0.

Provenance & Evidence