Sulfuric Acid → Methyl 4-bromo-5-methylthiophene-2-carboxylate

HRID 2046394Notes

Reaction equation

HRID 2046394 reaction equation
[Br:1][C:2]1[CH:3]=[C:4]([C:8]([OH:10])=[O:9])[S:5][C:6]=1[CH3:7].OS(O)(=O)=O.[C:16]([O-])(O)=O.[Na+]>CO>[Br:1][C:2]1[CH:3]=[C:4]([C:8]([O:10][CH3:16])=[O:9])[S:5][C:6]=1[CH3:7]

Participants

5

Reactant 3

HCID 1118Sulfuric AcidHCID 516892Sodium BicarbonateHCID 8188894-Bromo-5-methylthiophene-2-carboxylic acid

Product 1

HCID 18536848Methyl 4-bromo-5-methylthiophene-2-carboxylate

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

To a stirred solution of 4-bromo-5-methylthiophene-2-carboxylic acid (45 g, 204 mmol) in methanol (225 mL) was added concentrated H2SO4 (4.0 g, 41 mmol). The reaction mixture was heated to reflux overnight, cooled to room temperature, poured into saturated NaHCO3 (800 mL), and left to stir for 30 min. The precipitate was filtered, washed with water, and dried under high-vacuum to afford the title compound. 1H NMR (500 MHz, CDCl3) δ 7.61 (s, 1H); 3.88 (s, 3H); 2.45 (s, 3H). LRMS (APCI) calc'd for (C7H8BrO2S) [M+H]+, 234.9. found 234.9.

Workup

  1. temperatureThe reaction mixture was heated
  2. temperatureto reflux overnight
  3. waitleft
  4. filtrationThe precipitate was filtered
  5. washwashed with water
  6. customdried under high-vacuum

Sources & evidence

ORD record
ord-99a5c7aa5b3943e19eab1372611d4d5b
Source dataset
uspto-grants-2013_11
Patent number
US08592425B2

Reaction notes

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