Sodium Carbonate → 3-(9-hydroxynonyl)-2H-1,3-benzoxazine-2,4(3H)-dione

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

A mixture of 6.525 g (40 mmol) of carsalam, 10.26 g (44 mmol) of 9-bromo-1-nonanol, and 5.30 g (50 mmol) of sodium carbonate in 30 mL N,N-dimethylacetamide (DMA) was heated at 75-80° C. for 3 hours. TLC (eluent: ethyl acetate/heptane) indicated the reaction was completed. The reaction was carefully poured into a mixture of ice-water. The resulting white solid was stirred for 1 hour. It was collected on sintered glass funnel, washed with water, hexane and dried in vacuo to yield 9.80 g of 3-(9-hydroxynonyl)-2H-1,3-benzoxazine-2,4(3H)-dione (80%). To a slurry of 6.11 g (20 mmol) of 3-(9-hydroxynonyl)-2H-1,3-benzoxazine-2,4(3H)-dione in 10 mL of N,N-dimethylacetamide at room temperature was added 20.4 mL (20.4 mmol) of potassium t-butoxide in THF solution. The clear brown solution became very thick. More DMA (10 mL) was added, and the mixture was heated at reflux for 5 minutes. 0.664 g (4 mmol) of potassium iodide was added, followed by dropwise addition of 3.34 (20 mmol) of ethyl bromoacetate. The reaction was refluxed for 1 hour, cooled to about 35° C. and poured into ice-water. A gum resulted. The supernatant liquid was decanted and fresh water was added. That procedure was repeated twice. The gum was dissolved in THF. The THF solution was carefully poured into hexane. The resulting solid was collected, washed with hexane and dried in vacuo. The weight of the desired product was 2.36 g (35%). HPLC: 4.39 min.; Mp: 125-128° C. HNMR (M DSO d6): δ 1.25 (12H, m), 1.37 (2H, m), 1.53 (2H, m), 3.28 (2H, m), 3.36 (2H, t), 4.85 (2H, s), 7.07 (2H, m), 7.45 (1H, t), 7.88 (1H, d), 8.70 (1H, t). Anal. Calcd for C18H27NO6: C, 64.07; H, 8.07; N, 4.15. Found: C, 63.71; H, 8.29; N, 4.31.

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