Hydrogen Bromide → (2,6-Dichloro-4-methoxybenzyl)(triphenyl)phosphonium bromide

HRID 11070Notes

Reaction equation

HRID 11070 reaction equation
[Cl:1][C:2]1[CH:7]=[C:6]([O:8][CH3:9])[CH:5]=[C:4]([Cl:10])[C:3]=1[CH2:11]O.[C:13]1([P:19]([C:26]2[CH:31]=[CH:30][CH:29]=[CH:28][CH:27]=2)[C:20]2[CH:25]=[CH:24][CH:23]=[CH:22][CH:21]=2)[CH:18]=[CH:17][CH:16]=[CH:15][CH:14]=1.[BrH:32]>C(O)(=O)C.C1C=CC=CC=1>[Br-:32].[Cl:1][C:2]1[CH:7]=[C:6]([O:8][CH3:9])[CH:5]=[C:4]([Cl:10])[C:3]=1[CH2:11][P+:19]([C:20]1[CH:21]=[CH:22][CH:23]=[CH:24][CH:25]=1)([C:26]1[CH:31]=[CH:30][CH:29]=[CH:28][CH:27]=1)[C:13]1[CH:14]=[CH:15][CH:16]=[CH:17][CH:18]=1

Participants

6

Reactant 3

HCID 260Hydrogen BromideHCID 11776TriphenylphosphineHCID 14484725(2,6-Dichloro-4-methoxyphenyl)methanol

Product 1

HCID 87899136(2,6-Dichloro-4-methoxybenzyl)(triphenyl)phosphonium bromideYield 100%

Reagents, catalysts & solvents 2

HCID 176Acetic AcidSolventHCID 241BenzeneSolvent

Procedure

A solution of (2,6-dichloro-4-methoxyphenyl)methanol (3.00 g, 14.5 mmol) in 30% HBr in acetic acid (45 mL) was stirred at 20° C. for 3 h, then poured onto ice-water (120 mL) and extracted with pentane (6×100 mL). The extracts were washed with water (3×200 mL), backextracting with pentane (100 mL). Removal of the solvent gave the crude bromide as white crystals, which was immediately redissolved in benzene (80 mL) and treated with triphenylphosphine (5.70 g, 21.7 mmol), stirring at reflux for 15 h. After cooling, the precipitate was collected by filtration, washing thoroughly with dry benzene, then pentane, and dried under vacuum at 50° C. to give the phosphonium salt (521) as a white solid (7.75 g, 100%), mp (CH2Cl2/benzene) 188–190° C. 1H NMR (CDC3) δ 7.83–7.60 (m, 15H), 6.74 (s, 2H), 5.37 (d, J=13.5 Hz, 2H), 3.76 (s, 3H). Found: C, 58.40; H, 4.35. C26H22BrCl2OP requires C, 58.67; H, 4.17.

Workup

  1. additionpoured onto ice-water (120 mL)
  2. extractionextracted with pentane (6×100 mL)
  3. washThe extracts were washed with water (3×200 mL)
  4. customRemoval of the solvent
  5. customgave the crude bromide as white crystals, which
  6. temperatureat reflux for 15 h
  7. temperatureAfter cooling
  8. filtrationthe precipitate was collected by filtration
  9. washwashing thoroughly with dry benzene
  10. dry with materialpentane, and dried under vacuum at 50° C.

Sources & evidence

ORD record
ord-e43bb02ecf6b45f3a5d7445a8e13c68c
Source dataset
uspto-grants-2006_08
Patent number
US07094798B1

Reaction notes

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