To a flask containing 3-methyl-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)aniline (1.6 g, 6.96 mmol), the product of Step 2 (2.52 g, 6.96 mmol), dicyclohexyl[2′,4′,6′-tri(propan-2-yl)biphenyl-2-yl]phosphane (0.33 g, 0.70 mmol), Pd2(dba)3 (0.32 g, 0.35 mmol), cesium carbonate (6.80 g, 20.9 mmol) was added a degassed mixture of dioxane (23 mL) and water (2.3 mL). The solution was evacuated and then purged with argon 5 times and then heated at 100° C. overnight. The reaction was then cooled to room temperature, diluted with ethyl acetate, washed with aqueous saturated sodium bicarbonate, dried over magnesium sulfate, filtered and concentrated. Flash chromatography was used for purification to yield tert-butyl 4-[5-(3-amino-5-methylphenyl)-1,3-thiazol-2-yl]-4-hydroxycyclohexanecarboxylate. MS ESI: [M+H]+ m/z 389.
