Hydrochloric Acid → 2-t-Butyldimethylsilyl-3-formyl-6-methoxybenzofuran

HRID 1042585ノート

反応式

HRID 1042585 の反応式
[Si:1]([CH:8]1[C:12](=[CH:13][O:14][Si](C(C)(C)C)(C)C)[C:11]2[CH:22]=[CH:23][C:24]([O:26][CH3:27])=[CH:25][C:10]=2[O:9]1)([C:4]([CH3:7])([CH3:6])[CH3:5])([CH3:3])[CH3:2].Cl>CO>[Si:1]([C:8]1[O:9][C:10]2[CH:25]=[C:24]([O:26][CH3:27])[CH:23]=[CH:22][C:11]=2[C:12]=1[CH:13]=[O:14])([C:4]([CH3:7])([CH3:6])[CH3:5])([CH3:2])[CH3:3]

参加物

4

反応物 2

HCID 313Hydrochloric AcidHCID 672878412-t-Butyldimethylsilyl-3-(t-butyldimethylsilyloxymethylene)-6-methoxy-benzofuran

生成物 1

HCID 574219572-t-Butyldimethylsilyl-3-formyl-6-methoxybenzofuran

試薬・触媒・溶媒 1

HCID 887Methanol溶媒

実験手順

To a solution of 2-t-butyldimethylsilanyl-3-(t-butyldimethylsilanyloxymethylene)-6-methoxy-benzofuran (1.09 g, 2.69 mmol) in methanol (100 mL) was added concentrated hydrochloric acid (200 μL) and the reaction was stirred for 30 minutes (tlc), quenched with triethylamine (2 mL) and the solvent removed by distillation under vacuum. The residue was dissolved in dichloromethane (20 mL), washed with water (10 mL), dried over magnesium sulphate, concentrated under vacuum and co-distilled with toluene (20 mL); 1H NMR (300 MHz, CDCl3)-7.57 (d, 1H, J=8.57 Hz), 7.00 (d, 1H, J=2.17 Hz), 6.86 (dd, 1H, J=8.55, 2.22 Hz), 4.81 (s, 2H, CH2), 3.84 (s, 3H, OMe), 0.94 (s, 9H), 0.37 (s, 6H). The crude yellow paste (˜985 mg) was dissolved in dry dichloromethane (4 mL) and added to a stirred solution of Collin's reagent [chromium trioxide (1.01 g), pyridine (1.65 mL) in dry dichloromethane (30 mL)]. The suspension was stirred for 10 minutes, filtered and the residue washed with diethyl ether (20 mL). The filtrate was concentrated onto silica (10 g) and purified by flash chromatography (silica gel, eluent=hexane/diethyl-ether/triethylamine (90:9:1) to afford the title compound as a light yellow oil which crystallised on standing; (485 mg, 68%); 1H NMR (300 MHz, CDCl3) δ 10.25 (s, 1H, CHO), 8.06 (d, 1H, J=8.61 Hz), 7.03 (d, 1H, J=2.16 Hz), 6.95 (dd, 1H, J=8.60, 2.19 Hz), 3.84 (s, 3H, OMe), 0.97 (s, 9H), 0.46 (s, 6H); 13C NMR (75 MHz, CDCl3) δ 186.91 (CHO), 174.18, 159.19, 159.17, 132.82, 122.77, 117.34, 113.56, 95.36, 55.60, 27.04, 17.09, −5.24.

後処理

  1. customquenched with triethylamine (2 mL)
  2. customthe solvent removed by distillation under vacuum
  3. dissolutionThe residue was dissolved in dichloromethane (20 mL)
  4. washwashed with water (10 mL)
  5. dry with materialdried over magnesium sulphate
  6. concentrationconcentrated under vacuum and co-distilled with toluene (20 mL)
  7. dissolutionThe crude yellow paste (˜985 mg) was dissolved in dry dichloromethane (4 mL)
  8. additionadded to a stirred solution of Collin's reagent [chromium trioxide (1.01 g), pyridine (1.65 mL) in dry dichloromethane (30 mL)]
  9. stirringThe suspension was stirred for 10 minutes
  10. filtrationfiltered
  11. washthe residue washed with diethyl ether (20 mL)
  12. concentrationThe filtrate was concentrated onto silica (10 g)
  13. custompurified by flash chromatography (silica gel, eluent=hexane/diethyl-ether/triethylamine (90:9:1)

出典と根拠

ORDレコード
ord-f77b18221f61477ba6f808ccdcedd050
出典データセット
uspto-grants-2013_10
特許番号
US08557982B2

反応ノート

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