EP3825305A1 — Process for preparing lenvatinib

USPTO Abstract

Provided is a method for producing a compound represented by formula (IV) or a salt thereof, comprising: a step B of allowing a compound represented by formula (I) or a salt thereof to react with a compound represented by formula (II-A) or formula (II-B) wherein R 1 is a C 1-6 alkyl group, a C 2-6 alkenyl group, a C 6-10 aryl group, or a C 7-11 aralkyl group, wherein the C 1-6 alkyl group or the C 2-6 alkenyl group may have one to three substituents that may be the same or different and are selected from the group consisting of a halogen atom and a methoxy group, and wherein the C 6-10 aryl group or the C 7-11 aralkyl group may have one to three substituents that may be the same or different and are selected from the group consisting of a halogen atom, a methyl group, a methoxy group, and a nitro group; and X is a halogen atom, in the presence of a base to thereby obtain a compound represented by formula (III) wherein R 1 is the same group as above, and a step C of, after allowing the compound represented by formula (III) obtained in the step B to react without isolation with cyclopropylamine, precipitating and isolating a compound represented by formula (IV) or a salt thereof by introducing a hydrous organic solvent to a reaction solution.