Trifluoroacetic acid → 3-(4-Bromophenyl)propionic acid

t-Butyl acetate (159 mL, 1180 mmol) was added to lithium diisopropylamide (941 mmol) in tetrahydrofuran at -78° C. followed by 4-bromobenzylbromide (200 g, 784 mmol). The bath temperature was kept at -15° C. for 4 hours whereupon the reaction was quenched with ammonium chloride. The mixture was extracted with diethyl ether and the organic layer was washed with dilute hydrochloric acid, water, and brine, drying with sodium sulfate to yield a pale oil. This was refluxed with trifluoroacetic acid (150 mL, 1960 mmol) for 1 hour. The trifluoroacetic acid was removed under vacuum and the residue was partitioned between diethyl ether and aqueous sodium hydroxide. The aqueous layer was acidified with concentrated hydrochloric acid at 0° C. and extracted with diethyl ether. This organic layer was washed with water and brine and was dried over sodium sulfate to obtain a white solid after removing solvent under vacuum, (167 g, 93%), 132-134° C. m.p.

1. customwas quenched with ammonium chloride
2. extractionThe mixture was extracted with diethyl ether
3. washthe organic layer was washed with dilute hydrochloric acid, water, and brine
4. dry with materialdrying with sodium sulfate
5. customto yield a pale oil
6. customThe trifluoroacetic acid was removed under vacuum
7. customthe residue was partitioned between diethyl ether and aqueous sodium hydroxide
8. customwas acidified with concentrated hydrochloric acid at 0° C.
9. extractionextracted with diethyl ether
10. washThis organic layer was washed with water and brine
11. dry with materialwas dried over sodium sulfate
12. customto obtain a white solid
13. customafter removing solvent under vacuum, (167 g, 93%), 132-134° C. m.p.

ORD record

ord-0e1968f637944c0cad118034ed66011b

Source dataset

uspto-grants-1999_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05936000