Phosphorus tribromide → 2-(Bromomethyl)-4-methyl-1-nitrobenzene

HRID 925404Notes

Reaction equation

HRID 925404 reaction equation
[CH3:1][C:2]1[CH:3]=[CH:4][C:5]([N+:10]([O-:12])=[O:11])=[C:6]([CH2:8]O)[CH:7]=1.P(Br)(Br)[Br:14].C([O-])(O)=O.[Na+]>C(Cl)Cl>[Br:14][CH2:8][C:6]1[CH:7]=[C:2]([CH3:1])[CH:3]=[CH:4][C:5]=1[N+:10]([O-:12])=[O:11]

Participants

5

Reactant 3

HCID 24614Phosphorus tribromideHCID 516892Sodium BicarbonateHCID 568847(5-Methyl-2-nitrophenyl)methanol

Product 1

HCID 137762802-(Bromomethyl)-4-methyl-1-nitrobenzeneYield 95%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

5-methyl-2-nitrobenzoic acid (10.0 g, 55.2 mmol) were dissolved in THF (100 mL) followed by dropping 2.0 M borane dimethisulfide comples (110 mL, 221.1 mmol) and heating at 80° C. After 1.5 hours, 100 ml of 1 M HCl were dropped into this reaction system while cooling with ice and stirring. The system was extracted with ethyl acetate, and then was dried with Na2SO4 followed by concentration under reduced pressure and drying to obtain benzylic alcohol (9.1 g, 99% yield) as viscous colorless oil. (5-methyl-2-nitrophenyl) methanol (9.1 g, 54.5 mmol) were dissolved in dry CH2Cl2 (100 mL) followed by the addition of phosphorous tribromide (7.4 g, 27.3 mmol) and stirring at room temperature. After 30 minutes, saturated NaHCO3(aq. 100 mL) were added followed by stirring for 10 minutes and extracting with CH2Cl2 (200 ml×2). The organic phase was then concentrated under reduced pressure and dried to obtain the benzyl bromide analogue, 49, (11.9 g, 95% yield) as a white solid: mp 51-52° C.

Workup

  1. stirringby stirring for 10 minutes
  2. extractionextracting with CH2Cl2 (200 ml×2)
  3. concentrationThe organic phase was then concentrated under reduced pressure
  4. customdried

Sources & evidence

ORD record
ord-d62512760ca341f9a0576df531b2d460
Source dataset
uspto-grants-2016_03
Patent number
US09284299B2

Reaction notes

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