Ammonium Chloride → 4-[hydroxy-(2,3,4,5-tetramethoxy-6-methylphenyl)methyl]benzoic Acid Methylester

Temperatur

0 °C

To a solution of zinc chloride (1.91 mmol) in dry tetrahydrofuran (9.6 ml) was added under ice-cooling a 1.4 M methyllithium/ether solution (4.1 ml, 5.73 mmol), and the mixture was stirred at 0° C. for 30 minutes. The reaction mixture was cooled to −78° C., to which was added a solution of the compound (500 mg, 1.91 mmol) obtained in Step 1 in dry tetrahydrofuran (2.0 ml) and the mixture was further stirred at −78° C. for 4 hours. Subsequently, a solution of 2,3,4,5-tetramethoxy-6-methylbenzaldehyde (1.38 g, 5.73 mmol) in dry tetrahydrofuran (2 ml) was added and the mixture was stirred overnight at room temperature. To the reaction mixture an aqueous solution of saturated ammonium chloride (2.5 ml) was added at 0° C. After concentrating under reduced pressure, the concentrate was diluted with water and extracted three times with chloroform. After the organic layer was dried, the solvent was distilled off. After purification by a silica gel column chromatography (ethyl acetate : hexane=1:2), the title compound (237 mg, 0.63 mmol, yield 33%) was obtained.

1. temperatureThe reaction mixture was cooled to −78° C., to which
2. stirringthe mixture was further stirred at −78° C. for 4 hours
3. stirringthe mixture was stirred overnight at room temperature
4. concentrationAfter concentrating under reduced pressure
5. additionthe concentrate was diluted with water
6. extractionextracted three times with chloroform
7. customAfter the organic layer was dried
8. distillationthe solvent was distilled off
9. customAfter purification by a silica gel column chromatography (ethyl acetate : hexane=1:2)

ORD-Eintrag

ord-5bb86cae26ec4ef89bda7f4b16eceb50

Quelldatensatz

uspto-grants-2005_09

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US06943196B1