Hydrogen Bromide → 4-Bromo-2-(3,4-dichloro-phenyl)-butyric acid methyl ester

HRID 2377585Notes

Reaction equation

HRID 2377585 reaction equation
[Cl:1][C:2]1[CH:3]=[C:4]([CH:9]2[CH2:13][CH2:12][O:11][C:10]2=[O:14])[CH:5]=[CH:6][C:7]=1[Cl:8].[BrH:15].O=S(Cl)Cl.[C:20]1(C)C=CC=CC=1>C(O)(=O)C>[CH3:20][O:11][C:10](=[O:14])[CH:9]([C:4]1[CH:5]=[CH:6][C:7]([Cl:8])=[C:2]([Cl:1])[CH:3]=1)[CH2:13][CH2:12][Br:15]

Participants

6

Reactant 4

HCID 260Hydrogen BromideHCID 1140TolueneHCID 24386Thionyl ChlorideHCID 118064963-(3,4-Dichloro-phenyl)-dihydro-furan-2-one

Product 1

HCID 597634344-Bromo-2-(3,4-dichloro-phenyl)-butyric acid methyl esterYield 88%

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent2×

Procedure

A mixture of 10.2 g (44 mmol) 3-(3,4-dichloro-phenyl)-dihydro-furan-2-one, 55 mL HBr in acetic acid (33%) in 20 mL acetic acid was stirred at room temperature for 16 h. The mixture was poured onto ice/water and extracted with isopropylethyl acetate. The combined organic phases were washed with NaCl aq., dried with Na2SO4 and evaporated. 26.3 g (221 mmol) SOCl2 and 200 mL toluene was added and heated to 80° C. for 3 h. The mixture was evaporated to dryness and 100 mL methanol was added and stirred at room temperature for 30 min. The mixture was evaporated and subjected to column chromatography on silica eluting with a gradient formed from ethyl acetate and heptane. The combined product fractions were evaporated to yield 12.7 g (88%) of the title compound as light brown oil. MS (m/e): 335.5 (MH−).

Workup

  1. additionThe mixture was poured onto ice/water
  2. extractionextracted with isopropylethyl acetate
  3. washThe combined organic phases were washed with NaCl aq.
  4. dry with materialdried with Na2SO4
  5. customevaporated
  6. temperatureheated to 80° C. for 3 h
  7. customThe mixture was evaporated to dryness and 100 mL methanol
  8. additionwas added
  9. stirringstirred at room temperature for 30 min
  10. customThe mixture was evaporated
  11. customformed from ethyl acetate and heptane
  12. customThe combined product fractions were evaporated

Sources & evidence

ORD record
ord-1040a885e4cb457e868c5a9b77ffffe4
Source dataset
uspto-grants-2008_12
Patent number
US07470684B2

Reaction notes

Loading…