Ethyl 4-hydroxy-3-methyl-1-benzofuran-2-carboxylate → 5-Fluoro-4-hydroxy-3-methyl-benzofuran-2-carboxylic acid ethyl ester

HRID 843178ノート

反応式

HRID 843178 の反応式
[CH2:1]([O:3][C:4]([C:6]1[O:7][C:8]2[CH:15]=[CH:14][CH:13]=[C:12]([OH:16])[C:9]=2[C:10]=1[CH3:11])=[O:5])[CH3:2].[F:17][B-](F)(F)F.F[N+]1C(Cl)=CC=CC=1Cl>ClCCl>[CH2:1]([O:3][C:4]([C:6]1[O:7][C:8]2[CH:15]=[CH:14][C:13]([F:17])=[C:12]([OH:16])[C:9]=2[C:10]=1[CH3:11])=[O:5])[CH3:2]

参加物

4

反応物 2

HCID 748649Ethyl 4-hydroxy-3-methyl-1-benzofuran-2-carboxylateHCID 27373072,6-Dichloro-1-fluoropyridiniumtetrafluoroborate

生成物 1

HCID 540733565-Fluoro-4-hydroxy-3-methyl-benzofuran-2-carboxylic acid ethyl ester収率 27.7%

試薬・触媒・溶媒 1

HCID 6344Dichloromethane溶媒

実験手順

To a solution of 4-hydroxy-3-methyl-benzofuran-2-carboxylic acid ethyl ester (Joseph G. Atkinson et al., European patent application 0146243 (1985)) (700 mg) in dichloromethane (20 ml) was added 1-fluoro-2,6-dichloropyridinium tetrafluoroborate (807 mg) at room temperature and the mixture was stirred overnight. The reaction was quenched by the addition of water (10 ml), extracted with ethyl acetate (20 ml), washed with brine and dried over anhydrous magnesium sulfate. The mixture was separated by silica gel column chromatography developed by dichloromethane and methanol. 5-fluoro-4-hydroxy-3-methyl-benzofuran-2-carboxylic acid ethyl ester (210 mg) was obtained as a white solid. EI-MS: m/z 238 (MH+); 1H-NMR (CDCl3): δ 1.50 (3H, t, J=7.3 Hz), 2.82 (3H, s), 4.46 (2H, q, J=7.3 Hz), 6.99 (1H, dd, J=3.3 Hz, 8.9 Hz), 7.15 (1H, dd, J=8.9 Hz, 10.6 Hz). And 7-fluoro-4-methyl-benzofuran-2-carboxylic acid ethyl ester was obtained as a colorless oil. EI-MS: m/z 238 (MH+); 1H-NMR (CDCl3): δ 1.44 (3H, t, J=7.3 Hz), 2.76 (3H, s), 4.46 (2H, q, J=7.3 Hz), 6.47 (1H, dd, J=3.0 Hz, 8.6 Hz), 6.97 (1H, dd, J=8.6 Hz, 10.2 Hz).

後処理

  1. customThe reaction was quenched by the addition of water (10 ml)
  2. extractionextracted with ethyl acetate (20 ml)
  3. washwashed with brine
  4. dry with materialdried over anhydrous magnesium sulfate
  5. customThe mixture was separated by silica gel column chromatography

出典と根拠

ORDレコード
ord-47fb3f8450ff42f89170af0bd1b57867
出典データセット
uspto-grants-2002_04
特許番号
US06376491B1

反応ノート

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