Hydrogen Bromide → 2-Bromo-1,3-diethyl-5-methylbenzene

HRID 1662306Notes

Reaction equation

HRID 1662306 reaction equation
[BrH:1].C([C:4]1[CH:13]=[CH:12][CH:11]=CC=1N(CC)C)C.[Br-].[Na+].N(O[CH2:19][CH2:20][CH2:21][CH2:22][CH3:23])=O.Cl[C:25]1[CH:30]=CC=CC=1Cl>>[Br:1][C:19]1[C:13]([CH2:12][CH3:11])=[CH:4][C:22]([CH3:23])=[CH:21][C:20]=1[CH2:30][CH3:25]

Participants

6

Reactant 5

HCID 260Hydrogen BromideHCID 72391,2-DichlorobenzeneHCID 10026Pentyl nitriteHCID 253881Sodium BromideHCID 22759538HCID 22759538, compound

Product 1

HCID 115794912-Bromo-1,3-diethyl-5-methylbenzene

Procedure

48% aqueous hydrobromic acid (1.05 equiv.) is fed into a mixture of diethylmethylaniline (1.00 equiv.) and sodium bromide (0.10 equiv.) in o-dichlorobenzene. Water is then azeotroped off under vacuum. The resulting salt suspension is cooled to 50° C. n-Pentyl nitrite (1.05 equiv.) is fed subsurface at 50-55° C. over 2-hour period to afford 1-bromo-2,6-diethyl-4-methylbenzene as a yellow to light brown solution. The bottom aqueous phase is separated off. The organic phase is washed with 10% sodium carbonate solution (0.15 equiv.). n-Pentanol and o-dichlorobenzene are sequentially stripped off to produce the crude 1-bromo-2,6-diethyl-4-methylbenzene material with an assay of 90% and an isolated yield of 83-85%. The product can be further purified by vacuum distillation at 95° C./5 mmHg to give an assay of 97-99%.

Workup

  1. customWater is then azeotroped off under vacuum
  2. customat 50-55° C.
  3. customover 2-hour

Sources & evidence

ORD record
ord-a2f259e1b7924599a5d815ff6e84c815
Source dataset
uspto-grants-2011_10
Patent number
US08030529B2

Reaction notes

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