Hydroquinone diacetate → 10-(2,5-Dihydroxy-phenyl)-10-oxo-decanoic acid

Beteiligte Stoffe

Reaktionsschritte

To a 500 mL flask, equipped with mechanical stirrer and under inert atmosphere, was added the previously made Oxacycloundecane-2,11-dione (37.95 g, 206 mmol), 1,4-diacetoxy-benzene (20 g, 103 mmol), and 200 mL carbon disulfide. Aluminum (III) trichloride (68.7 g, 515 mmol) was added and the reaction stirred for 72 hours. Carbon disulfide was decanted away, and ice was carefully added until most of mixture was dissolved. The insoluble material was collected by suction filtration and washed with 2×100 mL of water. The solid was then dissolved in 50 mL of 1 M aqueous sodium hydroxide and stirred for 1 hour. The solution was acidified with 1 M aqueous hydrochloric acid until pH=2. The crude product precipitate was collected by filtration and was re dissolved in acetonitrile (50 mL) and methylene chloride (15 mL) and allowed to precipitate slowly over a week. The resulting brown powder was collected by filtration and recrystallized from 10:3 acetic acid:water. The product (0.8 g, 3%) was isolated by filtration. Found: C, 65.55, H, 7.69%; C16H22O5 requires C, 65.29; H, 7.53% 1H NMR (d6-DMSO): δ 12.0, s, 1H (COOH); δ 11.4, s, 1H (aryl-hydroxyl); δ 9.2, s, 1H (aryl-hydroxyl); δ 7.2 d, 1H (aryl H); δ 7.0, dd, 1H, (arylH); δ 6.8, d, 1H (aryl H's), 3.0, t, 2H(CH2 α to carbonyl); δ 2.2, t, 2H (CH2 β to COOH); δ 1.6, multiplet, 2H (CH2 β to carbonyl), δ 1.5, multiplet, 2H (CH2 β to COOH), δ 1.3, multiplet, 8H (rest of CH2's).

Herkunft & Nachweise