A freshly prepared solution of lithium diisopropylamide (12.83 mmol) in anhydrous tetrahydrofuran (15 mL) at −10° C. was added dropwise via cannula over 20 minutes to a −78° C. solution of N-(4-methoxybenzyl)-1-(thiazol-2-yl)cyclobutanamine (1.6 g, 5.83 mmol) (Example 112B) in anhydrous tetrahydrofuran (45 mL). The temperature was maintained below −70° C. during the addition, and after the addition, the reaction was stirred 45 minutes at −78° C. Tributyltin chloride (1.89 mL, 7.00 mmol) was then added dropwise. The cold bath was removed, and the reaction was allowed to warm to ambient temperature over 20 minutes. The reaction was quenched with saturated ammonium chloride, and the product was extracted with ethyl acetate. The combined extracts were washed with water and brine, dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure. The residue was purified by flash chromatography on silica gel, eluting with a gradient of 10% to 20% ethyl acetate in hexanes, to provide the title compound. MS ESI(+) m/z 565.1 [M+H]+.
