Crystal form of 6-(cyclopropanecarboxamido)-4-((2-methoxy-3-(1-methyl-1H-1,2,4-triazol-3-yl)phenyl)amino)-n-(methyl-d3) pyridazine-3-carboxamide

A method of preparing crystalline Form A of 6-(cyclopropanecarboxamido)-4-((2-methoxy-3-(1-methyl-1H-1,2,4-triazol-3-yl)phenyl) amino)-N-(methyl-d3)pyridazine-3-carboxamide, comprising:

• (a) mixing 10 grams of Compound (I), which is 6-(cyclopropanecarboxamido)-4-((2-methoxy-3-(1-methyl-1H-1,2,4-triazol-3-yl)phenyl) amino)-N-(methyl-d3)pyridazine-3-carboxamide, into 55 mL of NMP, thereby forming a slurry;
• (b) heating the slurry to obtain a solution of the Compound (I) in the NMP;
• (c) polish filtering the solution to obtain a filtrate;
• (d) heating the filtrate;
• (e) adding 30 mL of IPA to the heated filtrate;
• (f) allowing the temperature of the result of (e) to cool, and then adding seeds of Compound (I) in an amount of 1 wt %;
• (g) aging the result of (f);
• (h) adding 60 mL of IPA to the result of (g);
• (i) cooling the result of (h) to obtain a cold slurry;
• (j) aging the cold slurry;
• (k) filtering the aged cold slurry to obtain crystalline solids;
• (l) washing the crystalline solids twice with 40 mL of IPA each time, to obtain a wet cake;
• and
• (m) drying the wet cake to obtain crystalline Form A of 6-(cyclopropanecarboxamido)-4-((2-methoxy-3-(1-methyl-1H-1,2,4-triazol-3-yl)phenyl) amino)-N-(methyl-d3)pyridazine-3-carboxamide.