To a slurry of 3-(6-(1-(2,2-difluorobenzo[d][1,3]dioxol-5-yl)cyclopropanecarboxamido)-3-methylpyridin-2-yl)-t-butylbenzoate (1.0 eq) in MeCN (3.0 vol) was added water (0.83 vol) followed by concentrated aqueous HCl (0.83 vol). The mixture was heated to 45±5° C. After stirring for 24 to 48 hours, the reaction was complete, and the mixture was allowed to cool to ambient temperature. Water (1.33 vol) was added and the mixture stirred. The solid was collected by filtration, washed with water (2×0.3 vol), and partially dried on the filter under vacuum. The solid was dried to a constant weight (less than 1% difference) in a vacuum oven at 60° C. with a slight N2 bleed to afford 3-(6-(1-(2,2-difluorobenzo[d][1,3]dioxol-5-yl)cyclopropanecarboxamido)-3-methylpyridin-2-yl)benzoic acid.HCl as an off-white solid.
