5-chloro-4-hydroxyl-2(1H)-pyridone crystal form, preparation method and application thereof

The invention discloses a 5-chloro-4-hydroxyl-2(1H)-pyridone crystal form, a preparation method and application thereof. Intervals of crystal faces d of diffraction peaks in a powder X-ray diffraction diagram of P crystal forms of 5-chloro-4-hydroxyl-2(1H)-pyridone are 5.93, 4.79, 3.46, 3.42, 3.24, 2.97 and 2.77; and relative peak strengths corresponding to the diffraction peaks are 59, 27, 100, 35, 61, 16 and 22. An alkali-solution and acid-isolation crystallizing method is adopted in the preparation method of the P crystal forms. The crystal forms can be used as a dihydropyrimidine dehydrogenase inhibitor for preparing a drug for treating cancers. The crystal forms have the advantages of better thermodynamic stability, dissolution and bioavailability. The preparation method is simple and easy and suitable for industrialization application.