Maleic Anhydride → 4-[(6-chloro-1H-indazol-3-yl)amino]-4-oxo-2-butenoic acid

Participants

Reaction Conditions

Reaction Steps

585 mg of preground maleic anhydride are added to 1 g of 6-chloro-1H-indazole-3-amine in 30 cm3 of ortho-xylene. The reaction medium is refluxed at 145° C. for ten minutes and then cooled in a water bath. The insoluble material is filtered off and washed successively with 2×25 cm3 of ethyl acetate and then with 2×25 cm3 of diisopropyl ether. The solid is then dried under reduced pressure (90 Pa; 50° C.) to give 1 g of 4-[(6-chloro-1H-indazol-3-yl)amino]-4-oxo-2-butenoic acid (Z form) in the form of yellow crystals melting at 230° C.

Provenance & Evidence