Dimethyl Sulfate → Methyl 2-methoxy-3-methylbenzoate

HRID 1921915

Reaction equation

HRID 1921915 reaction equation
[CH3:1][C:2]1[CH:10]=[CH:9][CH:8]=[C:4]([C:5]([OH:7])=O)[C:3]=1[OH:11].[C:12](=O)([O-])[O-].[K+].[K+].COS([O:23][CH3:24])(=O)=O>CC(C)=O>[CH3:12][O:11][C:3]1[C:2]([CH3:1])=[CH:10][CH:9]=[CH:8][C:4]=1[C:5]([O:23][CH3:24])=[O:7]

Participants

5

Reactant 3

HCID 6497Dimethyl Sulfate2×HCID 67383-Methylsalicylic AcidHCID 11430Potassium Carbonate2×

Product 1

HCID 13229229Methyl 2-methoxy-3-methylbenzoate

Reagents, catalysts & solvents 1

HCID 180AcetoneSolvent

Procedure

To a mixture of 3-methyl-salicylic acid (200 g, 1.32 mol), anhydrous potassium carbonate (500 gram, 3.6 mol) and dry acetone (3.5 L) in a 5 liter round bottle flask, dimethylsulfate (DMS, 210 mL, 2.2 mol) was added in several portions. After stirring at room temperature overnight, the mixture was heated at reflux, and the reaction was monitored by TLC. In order to complete the etherification, further additions of DMS and K2CO3 may be necessary. When TLC indicated the completion of the reaction, the mixture was refluxed 4 more hours to destroy any remaining DMS. The mixture was filtered, and the filtrate was evaporated to remove the solvents. A pale yellow thick oil was obtained as the raw product, yield 215 g (91%). 1H NMR (500 MHz, CDCl3, 25° C.) δ: 2.26 (s, 3H, CH3), 3.78 (s, 3H, OCH3), 3.85 (s, 3H, OCH3), 6.98 (t, J=7.5, 1H, ArH), 7.27 (d, J=7.5, 1H, ArH), 7.58 (d, J=7.5, 1H, ArH); 13C NMR (500 MHz, CDCl3, 25° C.) δ: 15.7, 51.8, 61.1, 123.2, 124.3, 128.8, 132.4, 134.8, 158.1, 166.6.

Workup

  1. temperaturethe mixture was heated
  2. temperatureat reflux
  3. customthe completion of the reaction
  4. temperaturethe mixture was refluxed 4 more hours
  5. customto destroy any remaining DMS
  6. filtrationThe mixture was filtered
  7. customthe filtrate was evaporated
  8. customto remove the solvents

Sources & evidence

ORD record
ord-28af11f704094426a869ba0dc6830139
Source dataset
uspto-grants-2012_05
Patent number
US08173800B2

Linked notes

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