Abstract: The present application provide a compound represented by formula (I), a chiral enantiomer thereof or a pharmaceutically acceptable salt thereof, and a preparation method therefor, an intermediate for preparing the compound represented by formula (I), the chiral enantiomer thereof or the pharmaceutically acceptable salt thereof, and a preparation method therefor, a pharmaceutical composition comprising the compound represented by formula (I), the chiral enantiomer thereof or the pharmaceutically acceptable salt thereof, and pharmaceutical use of the compound represented by formula (I), the chiral enantiomer thereof or the pharmaceutically acceptable salt thereof or the pharmaceutical composition comprising the same. The compounds of the present application exhibit good JAK2 kinase inhibitory activity and high selectivity for JAK2 kinase.

Abstract: The present invention relates to a salt of a compound of formula (I), The salt is crystalline or amorphous phosphate, or crystalline or amorphous oxalate. Particularly, a crystal form B of the phosphate of the present invention has high crystallinity, low hygroscopicity and good stability, and the crystal form B of the phosphate is good in oral bioavailability, good in tolerance after long-term administration, difficult to induce hypoglycemia and good in inhibition effect on serum DPPIV.

Abstract: The present invention relates to a salt of a compound of formula (I), The salt is crystalline or amorphous phosphate, or crystalline or amorphous oxalate. Particularly, a crystal form B of the phosphate of the present invention has high crystallinity, low hygroscopicity and good stability, and the crystal form B of the phosphate is good in oral bioavailability, good in tolerance after long-term administration, difficult to induce hypoglycemia and good in inhibition effect on serum DPPIV.