Sodium Hydroxide → (2-Hydroxyphenyl)acetic acid

Temperature

180 °C

Solid pearl sodium hydroxide (as discrete spheres) (24 g) was suspended in `SOLVESSO` 200 (100 ml) at 25° C. (2-Chlorophenyl)acetic acid (17.0 g) was added to this in one portion and the mixture was stirred for 20 minutes at room temperature after which time copper sulphate pentahydrate (1.0 g) was added. The reaction mixture was then heated and stirred at 180° C. After 15 hours gas/liquid chromatography indicated that all the (2-chlorophenyl)acetic acid had been consumed. The reaction mixture was cooled to room temperature and during this process it thickened. (The pearl sodium hydroxide was still in discrete spheres). The reaction mixture was filtered and the residue washed twice with hexane. After briefly air drying the residue, it was dissolved in water. The water solution was filtered to remove some brown solid before being washed with ethyl acetate. Charcoal was then added to the water solution and the resulting mixture was filtered through `Hyflo` (`Hyflo` is a Trade Name of Trade Mark). The filtrate was acidified to pH 3.5 and a few oily specs were formed. These were filtered off. The resulting filtrate was extracted with ethyl acetate. The extracts were combined, dried and evaporated to give a crude product (10.5 g). The crude product was recrystallised from water and then recrystallised from acetic acid to give 2.7 g of (2-hydroxyphenyl)acetic acid as a crystalline solid (melting point 141.4°-142° C.) (theoretical m.pt. 147°-149° C.).

1. customat 25° C.
2. additionwas added to this in one portion
3. additionwas added
4. temperatureThe reaction mixture was then heated
5. customthe (2-chlorophenyl)acetic acid had been consumed
6. temperatureThe reaction mixture was cooled to room temperature and during this process it
7. filtrationThe reaction mixture was filtered
8. washthe residue washed twice with hexane
9. customAfter briefly air drying the residue, it
10. dissolutionwas dissolved in water
11. filtrationThe water solution was filtered
12. customto remove some brown solid
13. washbefore being washed with ethyl acetate
14. additionCharcoal was then added to the water solution
15. filtrationthe resulting mixture was filtered through `Hyflo` (`Hyflo`
16. customa few oily specs were formed
17. filtrationThese were filtered off
18. extractionThe resulting filtrate was extracted with ethyl acetate
19. customdried
20. customevaporated
21. customto give a crude product (10.5 g)
22. customThe crude product was recrystallised from water
23. customrecrystallised from acetic acid

ORD record

ord-fcefe58077a54fbea2efaafc53c2aa15

Source dataset

uspto-grants-1993_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05221772