To 4-[5-(3-methyl-5-{[4-(methylsulfanyl)pyrimidin-2-yl]amino}phenyl)-1,3-thiazol-2-yl]-1,4-diazepan-2-one (0.94 g, 2.204 mmol) stirring in dichloromethane (11 mL) at room temperature was added 3-chloroperbenzoic acid (1.587 g, 7.08 mmol). Stirred for 4 hr. at room temperature, diluted with 10% Na2S2O3 (aq.), and washed with sat. NaHCO3 (aq.) and brine. The organic extracts were dried (Na2SO4), filtered, and concentrated in vacuo. Purified by CombiFlash (100:0 to 0:20 dichloromethane:methanol) to afford impure 4-[5-(3-methyl-5-{[4-(methylsulfonyl)-2-pyrimidinyl]amino}phenyl)-1,3-thiazol-2-yl]-1,4-diazepan-2-one (0.188 g, 0.411 mmol, 18.6% yield) as an orange solid (contaminated with starting material). MS APCI: [M+H]+ m/z 459.1
