Hydrochloric Acid → 1-Fluoro-4-methoxy-2,5-dimethylbenzene

17.5 g of 5-fluoro-2-methoxy-4-methylbenzaldehyde was dissolved in 100 ml of methanol, 4.7 g of sodium borohydride was added to the suspension at 0° C. and the resulting mixture was stirred for 30 minutes. Acetone was added to the reaction mixture to decompose excess reagent. The resulting reaction mixture was evaporated and extracted with 150 ml of ethyl acetate. The organic layer was washed with brine, dried over anhydrous magnesium sulfate. After the desiccant was filtered off, the resulting mixture was evaporated to give white crystals. These crystals were dissolved in 50 ml of pyridine, followed by the addition of 19.6 ml of acetic anhydride. The resulting mixture was stirred at room temperature for 4 hours and poured into chilled dilute hydrochloric acid. The resulting mixture was stirred for 30 minutes, followed by the addition of ethyl acetate. The organic layer was separated, washed with water, a saturated aqueous solution of sodium bicarbonate and brine, dried over anhydrous magnesium sulfate. After the desiccant was filtered off, the resulting mixture was evaporated to give a solid. This solid was dissolved in 100 ml of ethyl acetate, followed by the addition of 3 g of 10% palladium/carbon (containing 50% of water). The resulting mixture was subjected to catalytic hydrogenation at ordinary temperature under normal pressure for 3 hours, and the resulting reaction mixture was filtered through Celite. The filtrate was concentrated, and the resulting crude product was purified by silica gel column chromatography to give 9.7 g of the title compound as a colorless oil.

1. customThe resulting reaction mixture
2. customwas evaporated
3. extractionextracted with 150 ml of ethyl acetate
4. washThe organic layer was washed with brine
5. dry with materialdried over anhydrous magnesium sulfate
6. filtrationAfter the desiccant was filtered off
7. customthe resulting mixture was evaporated
8. customto give white crystals
9. stirringThe resulting mixture was stirred at room temperature for 4 hours
10. additionpoured
11. stirringThe resulting mixture was stirred for 30 minutes
12. customThe organic layer was separated
13. washwashed with water
14. dry with materiala saturated aqueous solution of sodium bicarbonate and brine, dried over anhydrous magnesium sulfate
15. filtrationAfter the desiccant was filtered off
16. customthe resulting mixture was evaporated
17. customto give a solid
18. waitThe resulting mixture was subjected to catalytic hydrogenation at ordinary temperature under normal pressure for 3 hours
19. customthe resulting reaction mixture
20. filtrationwas filtered through Celite
21. concentrationThe filtrate was concentrated
22. customthe resulting crude product was purified by silica gel column chromatography

ORD record

ord-1c0fb872afa1465cb053caaa179b4c65

Source dataset

uspto-grants-2002_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06358995B1