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

HRID 424793Notes

Reaction equation

HRID 424793 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 0° C. solution of 5-(4-methoxy-2-methyl-phenyl)-4-methyl-thiophene-2-carboxylic acid methyl ester (540 mg, 2 mmol) in dichloromethane (30 mL) 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 evaporated. The residue is purified by column chromatography on silica gel eluting with 0-20% EtOAc in hexanes to give the title compound (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. customevaporated
  3. customThe residue is purified by column chromatography on silica gel eluting with 0-20% EtOAc in hexanes

Sources & evidence

ORD record
ord-67b066e5f48942a592bd5cf51a81f259
Source dataset
uspto-grants-2012_01
Patent number
US08106077B2

Reaction notes

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