p-Toluenesulfonic acid → 1-Bromo-3-(2-bromo-1,1-dimethoxyethyl)benzene

HRID 1481994Notes

Reaction equation

HRID 1481994 reaction equation
[Br:1][CH2:2][C:3]([C:5]1[CH:10]=[CH:9][CH:8]=[C:7]([Br:11])[CH:6]=1)=[O:4].[CH:12](OC)(OC)[O:13]C.[CH3:19]C1C=CC(S(O)(=O)=O)=CC=1>CO>[Br:11][C:7]1[CH:8]=[CH:9][CH:10]=[C:5]([C:3]([O:13][CH3:12])([O:4][CH3:19])[CH2:2][Br:1])[CH:6]=1

Participants

5

Reactant 3

HCID 6101p-Toluenesulfonic acidHCID 9005Trimethyl orthoformateHCID 5195852-Bromo-1-(3-bromophenyl)ethan-1-one

Product 1

HCID 1183088131-Bromo-3-(2-bromo-1,1-dimethoxyethyl)benzeneYield 100%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Conditions

Temperature
75 °C

Procedure

A solution of 2-bromo-1-(3-bromophenyl)ethanone (48.23 g, 174 mmol) in MeOH (200 ml) was treated with trimethyl orthoformate (57.5 mL) and pTsOH (1.650 g, 8.68 mmol) and heated at reflux (75° C. oil bath) under nitrogen for 2.5 hrs. The mixture was cooled, concentrated to a viscous oil, diluted with Et2O (250 mL), and washed with 2.0 M aq. K2CO3 (100 mL), then brine. The organic layer was dried (MgSO4), filtered, and concentrated under reduced pressure, affording the product (56.43 g, 174 mmol, 100% yield) as a mobile yellow oil. 1H NMR (500 MHz, CDCl3) δ 7.69 (t, J=1.8 Hz, 1H), 7.48 (ddd, J=7.9, 2.0, 1.0 Hz, 1H), 7.43 (dq, J=7.8, 0.9 Hz, 1H), 7.29-7.24 (m, 2H), 3.60 (s, 2H), 3.24 (s, 6H). 13C NMR (126 MHz, CDCl3) δ 141.0, 131.5, 130.6, 129.6, 125.9, 122.3, 100.8, 49.5, 35.0. LCMS (M+H-MeOH)=291.97.

Workup

  1. temperatureheated
  2. temperatureThe mixture was cooled
  3. concentrationconcentrated to a viscous oil
  4. additiondiluted with Et2O (250 mL)
  5. washwashed with 2.0 M aq. K2CO3 (100 mL)
  6. dry with materialThe organic layer was dried (MgSO4)
  7. filtrationfiltered
  8. concentrationconcentrated under reduced pressure

Sources & evidence

ORD record
ord-f2069faf7a6d4f4b854f1a701e74b190
Source dataset
uspto-grants-2016_08
Patent number
US09409922B2

Reaction notes

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