2,2,6-Trimethyl-4H-1,3-dioxin-4-one → HCID 69733596, compound

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Reaction Conditions

Reaction Steps

Alternatively, (R)-3-(5-acetoxyhexyl)-1,7-dimethylpyrido[2,3-d]pyrimidine-2,4,5(1H,3H,8H)-trione was prepared as follows: To a mixture of (R)-3-(5-acetoxyhexyl)-6-amino-1-methyluracil (2.1 g, 7.41 mmol) in xylenes (70 ml) heated to 160° C. was added over 30 minutes a solution of 2,2,6-trimethyl-4H-1,3-dioxin-4-one (2.0 ml, 15.3 mmol) in xylenes (30 ml). After stirring at 160° C. for 20 minutes, the mixture was cooled to room temperature and concentrated under reduced pressure. The residue was purified by column chromatography on silica gel eluting with 20% ethyl acetate-toluene to afford(R)-3-(5-acetoxyhexyl)-1,7-dimethylpyrido[2,3-d]pyrimidine-2,4,5(1H,3H,8H)-trione (1.37 g, 53% yield) as a clear oil. 1H NMR (300 MHz, CDCl3) δ 1.20 (d, 3H), 1.25-1.71 (m, 6H), 2.00 (s, 3H), 2.46 (s, 3H), 3.62 (s, 3H), 4.00 (t, 2H), 4.86 (sextet, 1H), 6.49 (s, 1H), 12.15 (s, 1H).13C NMR (75 MHz, CDCl3) δ 19.64, 20.96, 22.46, 25.02, 27.19, 29.15, 35.19, 40.67, 70.29, 94.48, 105.71, 150.09, 150.73, 164.92, 165.18, 167.82, 170.15.

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