p-Fluorophenylalanine → HCID 4478878, compound

Temperature

0 °C

To a cooled (0° C., ice/salt bath) solution of DL-4-fluorophenylalanine (5.0 g, 27.0 mmol) and potassium bromide (10.65 g, 90.0 mmol) in 3M sulphuric acid (45 ml) was added sodium nitrite (2.64 g, 38.0 mmol) portionwise over a 0.5 h period. The mixture was stirred at 0° C. for 1 h and then at room temperature for 1 h. The mixture was diluted with water (50 ml) and extracted with ether (2×75 ml). The combined extracts were washed with water (2×75 ml), dried (MgSO4) and evaporated in vacuo. The residue was chromatographed on silica gel eluting with CH2Cl2 /MeOH/NH3 (95:5:1) to give the title-acid (3.77 g, 56%), δ(250 MHz, CDCl3) 3.22 (1H, dd, J=14.3 and 7.2 Hz, CH of CH2), 3.43 (1H, dd, J=14.3 and 8.1 Hz, CH of CH2), 4.38 (1H, dd, J=7.2 and 8.1 Hz, CH), 6.98-7.31 (4H, m, Ar--H).

1. waitat room temperature for 1 h
2. extractionextracted with ether (2×75 ml)
3. washThe combined extracts were washed with water (2×75 ml)
4. dry with materialdried (MgSO4)
5. customevaporated in vacuo
6. customThe residue was chromatographed on silica gel eluting with CH2Cl2 /MeOH/NH3 (95:5:1)
7. customto give the title-acid (3.77 g, 56%), δ(250 MHz, CDCl3) 3.22 (1H, dd, J=14.3 and 7.2 Hz, CH of CH2), 3.43 (1H, dd, J=14.3 and 8.1 Hz, CH of CH2), 4.38 (1H, dd, J=7.2 and 8.1 Hz, CH), 6.98-7.31 (4H, m, Ar--H)

ORD record

ord-3268437bcb36405cab26ea976e23d5af

Source dataset

uspto-grants-1999_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05981529