Reaction #2460324

Reaction equation

2-bromo-α,α′-dibromo-p-xylene

triethyl phosphite

→

tetraethyl 2-bromo-p-xylenebisphosphonate

Conditions

Workup

1. 1
   OtherThe excess triethyl phosphite was removed under reduced pressure, 60 ml of hexanes
2. 2
   workup.ADDITIONwas added
3. 3
   Temperaturethe mixture was cooled at −78 ° C.
4. 4
   Otherwhite solid was formed on vigorous stirring
5. 5
   FiltrationThe solid was collected by rapid filtration
6. 6
   Washwashed three times with 20 ml of cool hexanes
7. 7
   Otherdried in vacuo
8. 8
   Otherisolated in 14.0 g (72.7%)
9. 9
   Otheryield as light yellow oil

Procedure

The mixture of 2-bromo-α,α′-dibromo-p-xylene (68) (14.43 g, 0.042 mol) and triethyl phosphite (145 ml) was refluxed at 180° C. overnight. The excess triethyl phosphite was removed under reduced pressure, 60 ml of hexanes was added, the mixture was cooled at −78 ° C. and white solid was formed on vigorous stirring. The solid was collected by rapid filtration, washed three times with 20 ml of cool hexanes, dried in vacuo and isolated in 14.0 g (72.7%) yield as light yellow oil.1H NMR (CDCl3, 500 MHz) δppm: 7.51 (s, br, 1H), 7.40 (dd, 3J=7.7 Hz, 4J=2.2 Hz, 1H), 7.21 (d, 3J=8.0 Hz, 1H) 4.04 (m, 8H, CH2), 3.38 (d, J=21.5 Hz, 2H, CH2), 3.09 (d, J=21.5 Hz, 2H, CH2), 1.25 (m, 12H, CH3).

Source