Reacción #42141

Ecuación de reacción

4-formyl-3-methoxybenzoic acid methyl ester

water

2-methyl-2-butene

NaClO2

→

title intermediate

Rendimiento 47.0%

2-Methoxyterephthalic Acid 4-Methyl Ester

Rendimiento 47.0%

Disolventes

DCM

tert-butyl alcohol

Condiciones de reacción

Tratamiento posterior

1. 1
   OtroThe solvent was then removed under reduced pressure
2. 2
   OtroThe crude reaction mixture
3. 3
   Extracciónthe product was extracted with 1N NaOH (200 mL)
4. 4
   LavadoThe aqueous layer was washed with DCM (200 mL)
5. 5
   Extracciónthe product extracted with DCM (200 mL)
6. 6
   LavadoThe organic layer was then washed with water (100 mL), NaCl (sat.) (100 mL)
7. 7
   Secadodried over MgSO4
8. 8
   Filtraciónfiltered
9. 9
   OtroThe solvent was removed under reduced pressure
10. 10
    Otroto use without further purification

Procedimiento

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).

Fuente