Patent ID: 8835633

Claim:
A process for the preparation of a hemi-tartrate of compound of formula (I-A) comprising: dissolving the compound of formula (I-A) in an organic solvent selected from the group consisting of: denatured ethanol, methanol and 2-propanol, forming a solution; heating said solution to a first temperature in the range of from about 35° C. to about reflux; adding L-tartaric acid to form a tartrate solution; and heating said tartrate solution to a second temperature in the range of from about 50° C. to about reflux to form a heated mixture; wherein said compound of formula (I-A) has a powder X-ray diffraction pattern that includes the following peaks: Pos. [°2θ] FWHM [°2θ] d-spacing [Å] Rel. Int. [%] 6.49 0.15 13.62 100 8.58 0.17 10.30 48 10.35 0.13 8.55 10 10.75 0.20 8.23 23 23.60 0.22 3.77 24.