Boron tribromide → 5-(4-Hydroxy-2-methyl-phenyl)-4-methyl-thiophene-2-carboxylic acid methyl ester

HRID 2261773Notes

Reaction equation

HRID 2261773 reaction equation
[CH3:1][O:2][C:3]([C:5]1[S:6][C:7]([C:11]2[CH:16]=[CH:15][C:14]([O:17]C)=[CH:13][C:12]=2[CH3:19])=[C:8]([CH3:10])[CH:9]=1)=[O:4].B(Br)(Br)Br>ClCCl>[CH3:1][O:2][C:3]([C:5]1[S:6][C:7]([C:11]2[CH:16]=[CH:15][C:14]([OH:17])=[CH:13][C:12]=2[CH3:19])=[C:8]([CH3:10])[CH:9]=1)=[O:4]

Participants

4

Reactant 2

HCID 25134Boron tribromideHCID 667042235-(4-Methoxy-2-methyl-phenyl)-4-methyl-thiophene-2-carboxylic acid methyl ester

Product 1

HCID 667041595-(4-Hydroxy-2-methyl-phenyl)-4-methyl-thiophene-2-carboxylic acid methyl esterYield 82%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent2×

Procedure

To a solution of 5-(4-methoxy-2-methyl-phenyl)-4-methyl-thiophene-2-carboxylic acid methyl ester (540 mg, 2 mmol) in dichloromethane (30 mL) at 0° C. is added BBr3 in dichloromethane (1N, 5.0 mL) and the mixture is stirred at ambient temperature overnight. The reaction is quenched by addition of methanol and is evaporated. The residue is purified by column chromatography (0-20% EtOAc in hexanes) to give 5-(4-hydroxy-2-methyl-phenyl)-4-methyl-thiophene-2-carboxylic acid methyl ester (420 mg, 82%). 1H NMR (CDCl3): δ 7.62 (s, 1H), 7.10 (d, 1H, J=7.9 Hz), 6.76 (s, 1H), 6.70 (d, 1H, J=7.9 Hz), 4.79 (bs, 1H), 3.88 (s, 3H), 2.15 (s, 3H), 2.02 (s, 3H).

Workup

  1. customThe reaction is quenched by addition of methanol
  2. customis evaporated
  3. customThe residue is purified by column chromatography (0-20% EtOAc in hexanes)

Sources & evidence

ORD record
ord-f7dba5f739f14f048969eb11421aeea4
Source dataset
uspto-grants-2010_12
Patent number
US07846960B2

Reaction notes

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