反应详情

1-Methyl-3-hydroxy-2(1H)-pyridinone (1) (6.25 g, 50 mmol) is mixed with anhydrous potassium carbonate (36 g, 0.26 mol). The vacuum dried mixture is put in a Parr bomb which is then filled with dry carbon dioxide gas (850 psi) and heated to 175°-185° C. for 3 days. The cooled bomb is opened and the resultant pale yellow solid is dissolved in ice water and acidified with 6N HCl to produce a beige crystalline product (7.42 g, 87.5%), m.p. 243°-245° C. (dec). 1H NMR (250 MHz, DMSO-d6): δ3.469 (s, 3H), 6.357 (d, 1H, J=7.33), 7.166 (d, 1H, J=7.19), 7.27 (s,br, 1H). 1H NMR (250 MHz, D2O-NaOD): d 3.342 (s, 3H), 6.176 (d, 1H, J=6.94), 6.487 (d, 1H, J=7.00). Anal. for C7H7NO4 (169.14): Calcd. (found): C, 49.71 (49.74); H, 4.17 (4.30); N 8.28 (8.16).

1. customThe vacuum dried mixture
2. additionis then filled with dry carbon dioxide gas (850 psi)
3. temperatureheated to 175°-185° C. for 3 days
4. dissolutionthe resultant pale yellow solid is dissolved in ice water