Processes for preparing ASK1 inhibitors
The present disclosure provides processes for the preparation of a compound of formula: which exhibits apoptosis signal-regulating kinase (“ASK1”) inhibitory activity and is thus useful in the treatment of diseases such as kidney disease, diabetic nephropathy and kidney fibrosis. The disclosure also provides compounds that are synthetic intermediates.
1. Crystalline 5-(4-cyclopropyl-1H-imidazol-1-1-2-fluoro-4-methylbenzoic acid hydrochloride (Compound of formula (D-a) Form I) characterized by an X-ray powder diffractogram comprising the following peaks: 7.3, 22.3, 23.4, 23.9, and 26.8 °2θ±0.2 °2θ, as determined on a diffractometer using Cu—Kα radiation at a wavelength of 1.5406 Å.
2. Compound of formula (D-a) Form I according to claim 1 , wherein the diffractogram further comprises peaks at 11.5, 13.4, 20.9, and 22.0 °2θ±0.2 °2θ.
3. Compound of formula (D-a) Form I according to claim 1 , wherein the diffractogram is substantially as shown in FIG. 1 .
4. Compound of formula (D-a) Form I according to claim 1 , characterized by a differential scanning calorimetry (DSC) curve that comprises an endotherm at about 210° C.
5. Compound of formula (D-a) Form I according to claim 4 , wherein the DSC curve is substantially as shown in FIG. 2 .