4-Bromophenol → 4-Bromophenyl phosphorodichloridate

Following the procedure described by McGuigan et al.,1993, Supra, a solution of p-bromophenol (13.20 g; 76.30 mmol) and distilled triethylamine (10.65 mL) in anhydrous Et2O (165 mL) was added dropwise into a vigorously stirred solution of phosphoryl chloride (8.5 mL; 91.2 mmol) in anhydrous Et2O (83 mL) at 0° C. over a period of three hours under nitrogen atmosphere. Subsequently, the resultant mixture was gradually warmed up to room temperature, stirred efficiently overnight at room temperature and then heated to reflux for two hours. The reaction mixture was cooled to room temperature and filtered under aspirator pressure. The precipitate was washed with anhydrous Et2O (2×50 mL). The combined Et2O layers were evaporated to dryness on rotary evaporator to yield crude 4c as a pale yellow oil which was then subjected to vacuum distillation to give pure 4c (14.05 g; 63.5% yield) as a colorless viscous oil (bp. 110-115° C./2 mm Hg). IR (Neat) 3095, 1481, 1303, 1187, 948, 829 cm−1. 1H NMR (300 MHz, CDCl3) δ7.50 (2H, d, J=9.0 Hz), 7.15 (2H, d, J=9.0 Hz). GC/MS (m/e) 290 (M+), 254 (M+—Cl), 173 (M+—POCl2, 81 Br), 171 (M+—POCl2,79Br), 156 (M+—PO2Cl2, 81Br), 154 (M+—PO2Cl2, 79Br).

1. temperatureheated
2. temperatureto reflux for two hours
3. temperatureThe reaction mixture was cooled to room temperature
4. filtrationfiltered under aspirator pressure
5. washThe precipitate was washed with anhydrous Et2O (2×50 mL)
6. customThe combined Et2O layers were evaporated to dryness on rotary evaporator

ORD record

ord-0185766db5fc4360ae926c3db58240f9

Source dataset

uspto-grants-2002_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06350736B1