4-[4-(6-fluoro-5-methyl-2-oxo-1,3-benzoxazol-3(2H)-yl)-1-piperidinyl]tetrahydro-2H-pyran-4-carbonitrile → 5-Fluoro-4-methyl-2-{[1-(4-methyltetrahydro-2H-pyran-4-yl)-4-piperidinyl]amino}phenol

Methylmagnesium iodide (3 mL, 9 mmol, 3 M in diethyl ether) was added to a suspension of 4-[4-(6-fluoro-5-methyl-2-oxo-1,3-benzoxazol-3(2H)-yl)-1-piperidinyl]tetrahydro-2H-pyran-4-carbonitrile (D4, 681 mg, 0.852 mmol) in tetrahydrofuran (10 mL) at 0° C. under argon. The reaction was stirred for 1 h at rt before being cooled to 0° C. and quenched with saturated aqueous NH4Cl (5 mL). The mixture was partitioned between ethyl acetate and water and the aqueous layer was extracted with ethyl acetate. The combined organics were dried (Na2SO4) and concentrated by rotary evaporation to give a brown oil, which was purified via chromatography (silica, dichloromethane to 0.5% ammonia/9.5% methanol/90% dichloromethane) to give a brown oil. This was further purified by high pH MDAP to give 5-fluoro-4-methyl-2-{[1-(4-methyltetrahydro-2H-pyran-4-yl)-4-piperidinyl]-amino}phenol (D5, 47 mg 17% yield) as a brown solid.