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

HRID 1253606ノート

反応式

HRID 1253606 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-eac1248646b14b6a8c344dbc39a693f4
出典データセット
uspto-grants-2013_06
特許番号
US08455496B2

反応ノート

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