Methanol → HCID 10953983, compound

HRID 2306899Notes

Reaction equation

HRID 2306899 reaction equation
[CH3:1][C:2]1[C:3]([O:5][C:6](=[O:9])[C:7]=1[CH3:8])=O.S(=O)(=O)(O)O.[C:15](=[O:18])([OH:17])[O-].[Na+].[CH3:20]O>C(Cl)Cl>[CH3:1]/[C:2](=[C:7](\[CH3:8])/[C:6]([O:5][CH3:3])=[O:9])/[C:15]([O:17][CH3:20])=[O:18]

Participants

6

Reactant 4

HCID 887Methanol2×HCID 1118Sulfuric Acid2×HCID 13010Dimethylmaleic anhydrideHCID 516892Sodium Bicarbonate

Product 1

HCID 10953983HCID 10953983, compoundYield 100%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

To a solution of 2 g (0.0158 mol) of 2,3-dimethylmaleic anhydride in 40 mL of methanol was added 0.2 mL of concentrated sulfuric acid. After refluxing for 7 days, the solution was diluted with 100 mL of methylene chloride, neutralized with aqueous sodium bicarbonate solution. The methylene chloride layer was washed with 30 mL of brine, the aqueous layer was extracted with methylene chloride four times (30 mL twice and 15 mL twice). The combined methylene chloride layer and extracts were dried over anhydrous magnesium sulfate, concentrated to give 2.11 g of crude product. 1H NMR check indicated about 25% of starting material existing, the crude mixture with 0.2 mL of concentrated sulfuric acid in 40 mL of methanol was heated at reflux again for 5 days. The solution was concentrated until 30% of methanol was left, neutralized with saturated sodium bicarbonate aqueous solution, followed by addition of 30 mL of brine solution, and the mixture was extracted with ethyl acetate four times (100 mL once, 30 mL three times). The combined ethyl acetate extracts were dried over anhydrous magnesium sulfate, concentrated to give 3.26 g of crude product 21 (˜100% yield). It was of satisfactory purity for the next step. 1H NMR (CDCl3) d 3.77 (s, 6H, OMe), 1.95 (s, 6H, Me)

Workup

  1. temperatureAfter refluxing for 7 days
  2. washThe methylene chloride layer was washed with 30 mL of brine
  3. extractionthe aqueous layer was extracted with methylene chloride four times (30 mL twice
  4. dry with materialThe combined methylene chloride layer and extracts were dried over anhydrous magnesium sulfate
  5. concentrationconcentrated
  6. customto give 2.11 g of crude product
  7. temperatureat reflux again for 5 days
  8. concentrationThe solution was concentrated until 30% of methanol
  9. waitwas left
  10. additionfollowed by addition of 30 mL of brine solution
  11. extractionthe mixture was extracted with ethyl acetate four times (100 mL once
  12. dry with materialThe combined ethyl acetate extracts were dried over anhydrous magnesium sulfate
  13. concentrationconcentrated

Sources & evidence

ORD record
ord-bd295c5fea2c4991b930e38b0497d88b
Source dataset
uspto-grants-2004_12
Patent number
US06828450B2

Reaction notes

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