Synthesis method of furoimidazopyridine compound, crystal form of furoimidazopyridine compound, and crystal form of salt thereof

Abstract

Provided is a method for synthesizing a compound 2-[(2R,5S)-5-[2-[(R)-1-hydroxyethyl]furo[3,2-b]imidazo[4,5-d]pyridin-1-yl]tetrahydropyran-2-yl]acetonitrile as a selective JAK1/TYK2 kinase inhibitor. The compound is prepared by nucleophilic substitution, palladium on carbon reduction, and cyclization reaction using 7-chloro-6-nitrofuro[3,2-b]pyridine as a starting material. The synthesis method has mild reaction conditions, high product yield, and high purity, and is suitable for industrial production. Further provided are a crystal form of the compound, crystal forma of its salts, and their preparation methods. The crystal form of the compound and the crystal forms of its salts have good physical and chemical properties and are suitable for drug development.