Hydrazine hydrate (1:1) → 4-(4-Bromo-2-chlorophenylamino)-5-chloro-6-hydrazinonicotinic acid ethyl ester

Participants

Reaction Conditions

Reaction Steps

4-(4-Bromo-2-chlorophenylamino)-5,6-dichloronicotinic acid ethyl ester (48) was prepared by standard methods from 4-(4-bromo-2-chlorophenylamino)-5,6-dichloronicotinic acid. Hydrazine monohydrate (0.59 mL, 12.16 mmol) was added to a solution of 4-(4-bromo-2-chlorophenylamino)-5,6-dichloronicotinic acid ethyl ester (48) (1.72 g, 4.05 mmol) in N,N-dimethylacetamide (20 mL). After stirring at 90° C. for 1 hour, the reaction mixture was cooled to room temperature and diluted with EtOAc. The organic layer was washed with water and brine, dried (Na2SO4) and concentrated. Purification by flash column chromatography using the Biotage system (20:1 CH2Cl2:EtOAc) provided the desired product (49) (307 mg, 18%).

Provenance & Evidence