Patent ID: 8362253

Claim:
A method of making crystalline N-[2,4-bis(1,1-dimethylethyl)-5-hydroxyphenyl]-1,4-dihydro-4-oxoquinoline-3-carboxamide·XX, the method comprising: dissolving N-[2,4-bis(1,1-dimethylethyl)-5-hydroxyphenyl]-1,4-dihydro-4-oxoquinoline-3-carboxamide in XX and then cooling the solution of N-[2,4-bis(1,1-dimethylethyl)-5-hydroxyphenyl]-1,4-dihydro-4-oxoquinoline-3-carboxamide and XX to provide crystalline N-[2,4-bis(1,1-dimethylethyl)-5-hydroxyphenyl]-1,4-dihydro-4-oxoquinoline-3-carboxamide·XX, wherein XX is selected from 2-methylbutyric acid, propylene glycol, isobutyric acid, propionic acid, and 2-propanol.