Reaktion #1605771

Reaktionsgleichung

2-hydroxy-4-methylbenzoic acid

K2CO3

KOH

HCl

→

2-methoxy-4-methylbenzoic acid

Lösungsmittel

acetone

MeOH

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturthe reaction mixture heated
2. 2
   Temperaturat reflux for 48 hrs
3. 3
   Filtrationwas filtered
4. 4
   Sonstigethe filtrate was evaporated
5. 5
   Sonstigeto give the crude methyl 2-methoxy-4-methylbenzoate
6. 6
   Temperaturthe solution heated
7. 7
   Temperaturat reflux 48 hrs
8. 8
   TemperaturAfter cooling the reaction mixture
9. 9
   Extraktionextracted with ethyl acteate
10. 10
    WaschenThe organic layer was washed with brine
11. 11
    Trocknendried over MgSO4
12. 12
    Filtrationfiltered
13. 13
    Sonstigeevaporated
14. 14
    SonstigeThe residue was triturated with Ethyl acetate/Hexane

Vorschrift

To a solution of 2-hydroxy-4-methylbenzoic acid (25 g, 0.164 mol) in acetone (350 mL) was added K2CO3 (68 g, 0.492 mmol) followed by MeI (41 mL, 0.656 mmol) and the reaction mixture heated at reflux for 48 hrs. After cooling to r.t. the reaction mixture was filtered and the filtrate was evaporated to give the crude methyl 2-methoxy-4-methylbenzoate. KOH (11.3 g, 1.2 eq) was dissolved in MeOH (300 mL) and the crude ester was added to the mixture and the solution heated at reflux 48 hrs. After cooling the reaction mixture was acidified with aq. HCl (1N) and extracted with ethyl acteate. The organic layer was washed with brine, dried over MgSO4, filtered and evaporated. The residue was triturated with Ethyl acetate/Hexane to give 20 g of 2-methoxy-4-methylbenzoic acid as a cream white solid (85% yield)

Quelle