To a stirred solution of 4-[2-[2-ethyl-4-methyl-6-oxo-1,6-dihydro-1-pyrimidinyl]ethoxy]aniline (2.80 g, 10.26 mmol) (obtained from preparation 22) in acetone (10 ml) was added aqueous HBr (47%, 1 ml) and stirred for 10 min. at 0° C. To the above reaction mixture a solution of NaNO2 (850 mg, 12.30 mmol) in water (1.7 ml) was added slowly dropwise at 0° C. and stirring was continued further for 30 min at the same temperature. To this reaction mixture, ethyl acrylate (6.77 ml, 62.0 mmol) was added and allowed to warm to 30° C. Catalytic amount of copper (I) iodide (20 mg) was added in one portion and the reaction mixture was stirred further for 1 h at 30° C. Acetone was removed under reduced pressure and the resultant residue was extracted with EtOAc (3×10 ml). The combined EtOAc layers were washed with dilute NH3 solution, water, followed by brine; dried over anhydrous Na2SO4 and concentrated to afford the crude compound which was purified by flash chromatography using 40% EtOAc/petroleum ether as eluent to yield the tide compound (2.47 g, 55%).
