Boron tribromide → HCID 25149592, compound

To a solution of diethyl 3,5-dichloro-4-(3′-iso-propyl-4′-methoxyphenoxy)benzylphosphonate (0.59 g, 1.28 mmol) in CH2Cl2 (10.0 mL) at −30° C. was added bromotrimethylsilane (2.53 mL, 19.2 mmol). The reaction mixture was stirred at room temperature for 16 h and the solvent was removed under reduced pressure. The residue was dissolved in dichloromethane (25.0 mL), cooled to −78° C. and to it was added BBr3 (19.0 mL, 19.0 mmol, 1.0 M solution in CH2Cl2). The reaction mixture was stirred at −78° C. for 10 min, allowed to warm to room temperature and stirred for 16 h. The reaction mixture was poured into ice, concentrated and extracted with ethyl acetate. The organic layer was washed with water (20 mL×2), dried over MgSO4 and filtered. The solvent was removed under reduced pressure to afford 3,5-dichloro-4-(3′-iso-propyl-4′-hydroxyphenoxy)benzylphosphonic acid as a brown solid (0.20 g, 40%): mp: 178-181° C.; LC-MS m/z=391 [C16H17Cl2O5P−H]−; 1H NMR (300 MHz, DMSO-d6): δ 9.08 (s, 1H), 7.48 (s, 2H), 6.72 (m, 2H), 6.25 (m, 1H), 3.18 (m, 1H), 3.00 (d, J=21.0 Hz, 2H), 3.11 (m, 1H), 1.14 (d, J=6.0 Hz, 6H); Anal. Calcd for (C16H17Cl2O5P+0.2 C4H8O2+0.5H2O): C, 48.30; H, 4.73. Found: C, 48.69, H, 5.16.

1. customthe solvent was removed under reduced pressure
2. dissolutionThe residue was dissolved in dichloromethane (25.0 mL)
3. temperaturecooled to −78° C. and to it
4. stirringThe reaction mixture was stirred at −78° C. for 10 min
5. temperatureto warm to room temperature
6. stirringstirred for 16 h
7. additionThe reaction mixture was poured into ice
8. concentrationconcentrated
9. extractionextracted with ethyl acetate
10. washThe organic layer was washed with water (20 mL×2)
11. dry with materialdried over MgSO4
12. filtrationfiltered
13. customThe solvent was removed under reduced pressure

ORD record

ord-4defbdc332664dce8d838b6eea73c7e2

Source dataset

uspto-grants-2009_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07514419B2