Triethyl phosphite → Diethyl (4-Bromobenzyl)phosphonate

HRID 1430716Notes

Reaction equation

[Br:1][C:2]1[CH:7]=[CH:6][C:5]([CH2:8]Br)=[CH:4][CH:3]=1.[P:10]([O:17]CC)([O:14][CH2:15][CH3:16])[O:11][CH2:12][CH3:13]>>[Br:1][C:2]1[CH:7]=[CH:6][C:5]([CH2:8][P:10](=[O:17])([O:14][CH2:15][CH3:16])[O:11][CH2:12][CH3:13])=[CH:4][CH:3]=1

Participants

Reactant 2

HCID 31215Triethyl phosphite

HCID 685274-Bromobenzyl bromide

Product 1

HCID 11077666Diethyl (4-Bromobenzyl)phosphonateYield 98%

Conditions

Temperature: 90 °C

Procedure

1-bromo-4-(bromomethyl)benzene (5.0 g, 20 mmol) and triethyl phosphite (51 mL, 300 mmol) were mixed in a round bottom flask and refluxed at 90° C. for 19 hours. Excess triethyl phosphite was removed under reduced pressure and the product purified by flash chromatography (1:1 Hexane/EtOAc) to give compound 16. 16: 98% yield; colorless liquid; 1H NMR (400 MHz, CDCl3) δ 7.30 (d, 2H, J=7.5 Hz), 7.05 (d, 2H, J=7.6 Hz), 3.99-3.88 (m, 4H), 2.99 (s, 1H), 2.94 (s, 1H), 1.12 (t, 6H, J=106.9 Hz); 13C NMR (100 MHz, CDCl3) δ 131.7, 131.6, 131.5, 121.0, 62.3, 34.0, 32.0, 16.5; HRMS Calc for C11H16BrO3P (M+H)+ 307.0097 found 307.0093.

Workup

customExcess triethyl phosphite was removed under reduced pressure
customthe product purified by flash chromatography (1:1 Hexane/EtOAc)

Sources & evidence

ORD record: ord-22a11821941346fc82f5d7d4fba93f06
Source dataset: uspto-grants-2015_01
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08940918B2

Reaction notes

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