To a vigorously stirred mixture of water (20 ml) and a solution of (E)-methyl 2-[2-(6-(2-cyanophenoxy)pyrimidin-4-yloxy)phenyl]-3-methoxypropenoate (3.2 g, 7.94 mmol) in dichloromethane (20 ml) was added potassium permanganate (2.5 g, 15.9 mmol) in one portion and tetra-n-hexylammonium hydrogen sulphate (200 mg). The reaction mixture was stirred overnight (16 hours) and then filtered. The filter was washed through with ether and water and then the combined filtrates were extracted with ether (×3). The ether extracts were washed with water (×3) and brine (×1), dried, filtered and evaporated. The residue was chromatographed (eluent dichloromethaneacetone, 98:2). Recrystallisation (ether-pentane) of the major component afforded methyl 2-[2-(6-(2-cyanophenoxy)pyrimidin-4-yloxy)phenyl]-ketoacetate (2.105 g, 71%) as a white crystalline solid; mp 96°-97° C.; 1H NMR (CDCl3) δ 3.83(3H,s), 6.61(1H,s), 7.27-7.47(4H,m), 7.67-7.76(3H,m), 8.02(1H,dd), 8.39(1H,s) ppm; IR maxima 2234(CN), 1743(CO, ester); 1688(CO, ketone)cm-1.
