To a round-bottom flask, which was purged and maintained with an inert atmosphere of nitrogen, was added a solution of 4-(1-(5-(2-bromoacetyl)-4-cyclobutyl-2-methylbenzoyl)piperidin-4-yl)benzonitrile (compound 235.2, 100 mg, 0.210 mmol, 1.00 equiv) in CH3CN (5 mL). Propionimidamide hydrochloride (22.8 mg, 1.00 equiv) and potassium carbonate (86.6 mg, 0.63 mmol, 3.00 equiv) were added to the reaction. The resulting solution was stirred for 3 h at 80° C., then cooled to room temperature and concentrated in vacuo. The residue was dissolved in 20 mL of water. The mixture was extracted with 2×20 mL of ethyl acetate and the combined organic layers were dried over anhydrous sodium sulfate and concentrated in vacuo. The crude product (˜100 mg) was purified by Prep-HPLC with the following conditions (1#-Pre-HPLC-001(SHIMADZU)): Column, SunFire Prep C18, 19*150 mm 5 um; mobile phase, water with 0.05% TFA and CH3CN (29.0% CH3CN up to 43.0% in 7 min, up to 100.0% in 3 min, down to 29.0% in 2 min); Detector, Waters 2489 254&220 nm. The fractions containing pure compound were combined and lyophilized to yield 43 mg (44%) of the title compound as a white solid. m/z (ES+) 453 (M+H)+. 1H NMR (300 MHz, CD3OD): δ 7.68 (d with fine structure, J=7.8 Hz, 2H), 7.56-7.53 (m, 4H), 7.30 and 7.20 (2 singlets, amide rotamers, Ar—H, 1H), ˜4.9 (1H partially obscured by water peak), 3.84-3.70 (m, 1H), 3.70-3.53 (m, 1H), 3.33-3.19 (m, 1H partially obscured by methanol solvent peak), 3.13-2.92 (m, 4H), 2.48 & 2.38 (2 singlets, amide rotamers, Ar—CH3, 3H), 2.29-2.11 (m, 4H), 2.11-1.93 (m, 2H), 1.93-1.72 (m, 3H), 1.72-1.53 (m, 1H), 1.45 (t, 3H).
