Bromine → 2-Bromo-7-acetoxy-3-(3,4,5-trimethoxybenzoyl)-6-methoxybenzofuran

HRID 218826Notes

Reaction equation

HRID 218826 reaction equation
[Si]([C:8]1[O:9][C:10]2[C:30]([O:31][C:32](=[O:34])[CH3:33])=[C:29]([O:35][CH3:36])[CH:28]=[CH:27][C:11]=2[C:12]=1[C:13](=[O:26])[C:14]1[CH:19]=[C:18]([O:20][CH3:21])[C:17]([O:22][CH3:23])=[C:16]([O:24][CH3:25])[CH:15]=1)(C(C)(C)C)(C)C.[Br:37]Br>ClCCCl>[Br:37][C:8]1[O:9][C:10]2[C:30]([O:31][C:32](=[O:34])[CH3:33])=[C:29]([O:35][CH3:36])[CH:28]=[CH:27][C:11]=2[C:12]=1[C:13](=[O:26])[C:14]1[CH:19]=[C:18]([O:20][CH3:21])[C:17]([O:22][CH3:23])=[C:16]([O:24][CH3:25])[CH:15]=1

Participants

4

Reactant 2

HCID 24408BromineHCID 247865592-t-Butyldimethylsilyl-7-acetoxy-3-(3,4,5-trimethoxybenzoyl)-6-methoxybenzofuran

Product 1

HCID 247865602-Bromo-7-acetoxy-3-(3,4,5-trimethoxybenzoyl)-6-methoxybenzofuranYield 81%

Reagents, catalysts & solvents 1

HCID 111,2-DichloroethaneSolvent

Procedure

To a stirred solution of 2-t-butyldimethylsilyl-7-acetoxy-3-(3,4,5-trimethoxybenzoyl)-6-methoxybenzofuran (120 mg, 0.44 mmol) in 1,2-dichloroethane (1 mL) at room temperature under nitrogen was added bromine (12 μl, 0.44 mmol) dropwise and the reaction mixture was stirred at this temperature for 10 minutes. After this time the reaction was quenched with saturated sodium thiosulfate solution, extracted with ethyl acetate (20 mL), dried over magnesium sulfate and the solvent removed by distillation under vacuum. The crude product was purified by silica gel column chromatography (eluent=Hexane:diethyl ether; 8:2-7:3) to afford the title compound as a colourless crystalline solid (91 mg, 81%); 1H NMR (300 MHz, CDCl3) δ 7.40(d, 1H, J=8.70 Hz), 7.14(s, 2H, benzoyl-Hs), 6.98(d, 1H, J=8.75 Hz), 3.94(s, 3H, OMe), 3.89(s, 3H, OMe), 3.86(s, 6H, 2×OMe), 2.43(s, 3H); 13C NMR (75 MHz, CDCl3) δ 187.95(CO), 167.71, 152.75, 149.54, 147.49, 142.59, 131.92, 131.80, 123.91, 121.84, 119.89, 117.72, 109.89, 106.92, 60.69, 56.61, 56.00, 20.09.

Workup

  1. customAfter this time the reaction was quenched with saturated sodium thiosulfate solution
  2. extractionextracted with ethyl acetate (20 mL)
  3. dry with materialdried over magnesium sulfate
  4. customthe solvent removed by distillation under vacuum
  5. customThe crude product was purified by silica gel column chromatography (eluent=Hexane:diethyl ether; 8:2-7:3)

Sources & evidence

ORD record
ord-bbb6dce55c6f46b4b54ece06c5bc49ca
Source dataset
uspto-grants-2012_06
Patent number
US08198466B2

Reaction notes

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