Reaktion #42141

Reaktionsgleichung

4-formyl-3-methoxybenzoic acid methyl ester

water

2-methyl-2-butene

NaClO2

→

title intermediate

Ausbeute 47.0%

2-Methoxyterephthalic Acid 4-Methyl Ester

Ausbeute 47.0%

Lösungsmittel

DCM

tert-butyl alcohol

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeThe solvent was then removed under reduced pressure
2. 2
   SonstigeThe crude reaction mixture
3. 3
   Extraktionthe product was extracted with 1N NaOH (200 mL)
4. 4
   WaschenThe aqueous layer was washed with DCM (200 mL)
5. 5
   Extraktionthe product extracted with DCM (200 mL)
6. 6
   WaschenThe organic layer was then washed with water (100 mL), NaCl (sat.) (100 mL)
7. 7
   Trocknendried over MgSO4
8. 8
   Filtrationfiltered
9. 9
   SonstigeThe solvent was removed under reduced pressure
10. 10
    Sonstigeto use without further purification

Vorschrift

To a stirred solution of 4-formyl-3-methoxybenzoic acid methyl ester (5.0 g, 26 mmol; prepared as described in Preparation 17) in tert-butyl alcohol (200 mL) was added NaH2PO4-2H2O (3.6 g, 26 mmol), water (50 mL), 2-methyl-2-butene (11 mL, 104 mmol), and finally NaClO2 (7.02 g, 78 mmol). The reaction was allowed to stir at room temperature for 4 hours. The solvent was then removed under reduced pressure. The crude reaction mixture was then dissolved in DCM (200 mL) and the product was extracted with 1N NaOH (200 mL). The aqueous layer was washed with DCM (200 mL) and then neutralized with 6N HCl (˜40 mL) and the product extracted with DCM (200 mL). The organic layer was then washed with water (100 mL), NaCl (sat.) (100 mL), dried over MgSO4 and then filtered. The solvent was removed under reduced pressure. The crude material was sufficiently pure to use without further purification. The title intermediate was obtained in 47% yield (2.4 g, 12.3 mmol).

Quelle