Acetic Anhydride → 6-Benzofurancarboxylic acid, 4-(acetyloxy)-2-methyl-, ethyl ester

HRID 1027694ノート

反応式

HRID 1027694 の反応式
[CH2:1]([O:3][C:4](/[C:6](=[CH:11]/[C:12]1[O:13][C:14]([CH3:17])=[CH:15][CH:16]=1)/[CH2:7][C:8]([OH:10])=O)=[O:5])[CH3:2].[C:18](OC(=O)C)(=[O:20])[CH3:19].C([O-])(=O)C.[Na+]>>[C:18]([O:10][C:8]1[C:16]2[CH:15]=[C:14]([CH3:17])[O:13][C:12]=2[CH:11]=[C:6]([C:4]([O:3][CH2:1][CH3:2])=[O:5])[CH:7]=1)(=[O:20])[CH3:19]

参加物

4

反応物 3

HCID 7918Acetic AnhydrideHCID 517045Sodium AcetateHCID 59560308(E)-3-(ethoxycarbonyl)-4-(5-methylfuran-2-yl)but-3-enoic acid

生成物 1

HCID 595600946-Benzofurancarboxylic acid, 4-(acetyloxy)-2-methyl-, ethyl ester収率 152.7%

実験手順

To a vigorously stirred solution of (E)-3-(ethoxycarbonyl)-4-(5-methylfuran-2-yl)but-3-enoic acid (I-1a: 326.6 g, 1.371 mol) in acetic anhydride (1.77 L, 18.72 mol) at room temperature was added sodium acetate (193 g, 2350 mmol) in one portion. The reaction mixture was then heated at reflux for 2.5 hours. After cooling to room temperature, the mixture was concentrated in vacuo (all batches were combined at this point). The resulting residue was suspended in dichloromethane (1.5 L) and filtered, washing the solids with dichloromethane (3×500 mL). The combined filtrate and washings were then washed with sodium hydrogencarbonate (2×1 L of a saturated aqueous solution) and brine (2 L), then concentrated in vacuo to give desired ethyl 4-acetoxy-2-methylbenzofuran-6-carboxylate (I-1b: 549.03 g, quantitative). 1H NMR (CDCl3, 300 MHz) δ ppm 8.00-7.99 (m, 1H), 7.64 (d, 1H), 6.32-6.32 (m, 1H), 4.38 (q, 2H), 2.47 (d, 3H), 2.37 (s, 3H), 1.39 (t, 3H).

後処理

  1. temperatureThe reaction mixture was then heated
  2. temperatureat reflux for 2.5 hours
  3. concentrationthe mixture was concentrated in vacuo (all batches
  4. filtrationfiltered
  5. washwashing the solids with dichloromethane (3×500 mL)
  6. washThe combined filtrate and washings were then washed with sodium hydrogencarbonate (2×1 L of a saturated aqueous solution) and brine (2 L)
  7. concentrationconcentrated in vacuo

出典と根拠

ORDレコード
ord-fd82e14a1e9349a8bd3730f3cdf32650
出典データセット
uspto-grants-2014_05
特許番号
US08735396B2

反応ノート

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