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To a suspension of sodium hydride (0.75 g, 80% dispersion in oil) and 1,3-dimethylbarbituric acid (1.56 g, 0.01 mol) in acetonitrile (10 mL) was added a solution of ethyl 2-(bromomethyl)propenoate (3.86 g, 0.02 mol) in acetonitrile (5 mL). The resulting mixture was allowed to stir at room temperature under nitrogen overnight. Thin layer chromatography (ethyl acetate/petroleum spirit: 1/4) indicated all the starting materials had been consumed. Water (30 mL) was added and the slightly pink solution was extracted three times with ethyl acetate (3×30 mL). The combined organic layer was washed with water, brine and then dried over anhydrous magnesium sulfate. After removal of solvent, purification by column chromatography (silica-gel 100 g, ethyl acetate:pet. spirit 40°-60° C. 1:4) gave pure product (11) (3.20 g, 84%) as a colourless liquid which solidified when stored in the freezer. 1 H-NMR (CDCl3) δ(ppm): 1.22 (t, 6H); 3.00 (s, 4H); 3.20 (s, 6H); 4.08 (q, 4H); 5.50 (s, 2H) and 6.15 (s, 2H). 13C-NMR (CDCl3) δ(ppm): 13.9, 28.2, 39.9, 55.4, 61.0, 128.2, 135.2, 151.0, 166.2 and 169.9.

1. customhad been consumed
2. additionWater (30 mL) was added
3. extractionthe slightly pink solution was extracted three times with ethyl acetate (3×30 mL)
4. washThe combined organic layer was washed with water, brine
5. dry with materialdried over anhydrous magnesium sulfate
6. customAfter removal of solvent, purification by column chromatography (silica-gel 100 g, ethyl acetate:pet. spirit 40°-60° C. 1:4)