Xinafoate salt of N4-(2,2-difluoro-4H-benzo[1,4]oxazin-3-one)-6-yl]-5-fluoro-N2-[3-(methylaminocarbonylmethyleneoxy) phenyl]2,4-pyrimidinediamine

1. A xinafoate salt of N4-[(2,2-difluoro-4H-benzo[1,4]oxazin-3-one)-6-yl]-5-fluoro-N2-[3-(methylaminocarbonylmethyleneoxy)phenyl]-2,4-pyrimidinediamine.

2. The xinafoate salt of claim 1 having shifts at about −69.2, −72.4 and −164.0 ppm when characterized by fluorine solid state NMR referenced to an external sample of trifluoroacetic acid (50% by volume in H 2 O) assigned a resonance at −76.54 ppm.

3. A pharmaceutical composition comprising the xinafoate salt of claim 1 and a pharmaceutically acceptable excipient.

4. A method of treating asthma in a mammal, the method comprising administering to the mammal in need thereof a therapeutically effective amount of the xinafoate salt of claim 1 .

5. A process for preparing the xinafoate salt of claim 1 comprising dissolving N4-[(2,2-difluoro-4H-benzo[1,4]oxazin-3-one)-6-yl]-5-fluoro-N2-[3-(methylaminocarbonylmethyleneoxy)phenyl]-2,4-pyrimidinediamine and between 1 and 1.1 molar equivalents 1-hydroxy-2-naphthoic acid in the minimum amount of a suitable organic solvent and cooling the solution slowly, optionally with stirring, until the salt precipitates from the solution.

6. The process of claim 5 wherein the solvent is acetone, acetonitrile or methyl ethyl ketone (MEK), each optionally containing a small amount of water.

7. The process of claim 6 wherein the solvent is methyl ethyl ketone containing about 5% by volume of water.

8. The compound of claim 1 formulated as a dry powder for administration from a dry powder inhaler.

9. A product comprising a dry powder inhaler and a xinafoate salt of N4-[(2,2-difluoro-4H-benzo[1,4]oxazin-3-one)-6-yl]-5-fluoro-N2-[3-(methylaminocarbonylmethyleneoxy)phenyl]-2,4-pyrimidinediamine formulated as a dry powder for administration from a dry powder inhaler.