Réaction #42141

Équation de réaction

4-formyl-3-methoxybenzoic acid methyl ester

water

2-methyl-2-butene

NaClO2

→

title intermediate

Rendement 47.0%

2-Methoxyterephthalic Acid 4-Methyl Ester

Rendement 47.0%

Solvants

DCM

tert-butyl alcohol

Conditions de réaction

Traitement

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

Mode opératoire

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).

Source