Methanol → Methyl 6-bromo-3-methylbenzofuran-2-carboxylate

HRID 1773230Notes

Reaction equation

HRID 1773230 reaction equation
[Br:1][C:2]1[CH:14]=[CH:13][C:5]2[C:6]([CH3:12])=[C:7]([C:9]([OH:11])=[O:10])[O:8][C:4]=2[CH:3]=1.O=S(Cl)Cl.[CH3:19]O>>[Br:1][C:2]1[CH:14]=[CH:13][C:5]2[C:6]([CH3:12])=[C:7]([C:9]([O:11][CH3:19])=[O:10])[O:8][C:4]=2[CH:3]=1

Participants

4

Reactant 3

HCID 887MethanolHCID 24386Thionyl ChlorideHCID 42282014HCID 42282014, compound

Product 1

HCID 70554114Methyl 6-bromo-3-methylbenzofuran-2-carboxylate

Procedure

To a suspension of 6-bromo-3-methylbenzofuran-2-carboxylic acid (5 g, 19.6 mmol) in 196 mL of MeOH was added SOCl2 (2.9 mL, 39.2 mmol). After the mixture was heated to reflux for 1 hr, the reaction solution became clear, and the color changed to green. The mixture was concentrated to remove part of solvent, and the color of the solution changed to yellow. After cooling to room temperature a white PPT formed, and the suspension was filtered, and the solid was washed with small amounts of EtOAc. The solid was dried under vacuum at 50° C. to give pure methyl 6-bromo-3-methylbenzofuran-2-carboxylate (3.56 g). LCMS retention time=1.58 minutes (LC method 3); MS (m+1)=270.9. 1H NMR (400 MHz, CHLOROFORM-d) δ 2.59 (s, 3H), 3.99 (s, 3H), 7.41-7.47 (m, 1H), 7.48-7.53 (m, 1H), 7.72 (d, J=1.5 Hz, 1H).

Workup

  1. temperatureAfter the mixture was heated
  2. temperatureto reflux for 1 hr
  3. concentrationThe mixture was concentrated
  4. customto remove part of solvent
  5. customformed
  6. filtrationthe suspension was filtered
  7. washthe solid was washed with small amounts of EtOAc
  8. customThe solid was dried under vacuum at 50° C.

Sources & evidence

ORD record
ord-7f89f2ea39c9423ca8c24d1c4ce896c3
Source dataset
uspto-grants-2016_02
Patent number
US09255093B2

Reaction notes

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