Catechol → 4-Fluorobenzo[d][1,3]dioxole

HRID 2249375Notes

Reaction equation

HRID 2249375 reaction equation
BrCBr.O.[F:5][C:6]1[CH:12]=[CH:11][CH:10]=[C:8]([OH:9])[C:7]=1[OH:13].[C:14]1(C(=CC=CC=1)O)O>[Cl-].C[N+](CCCCCCCC)(CCCCCCCC)CCCCCCCC.[OH-].[Na+].C(Cl)Cl>[F:5][C:6]1[CH:12]=[CH:11][CH:10]=[C:8]2[O:9][CH2:14][O:13][C:7]=12

Participants

8

Reactant 4

HCID 289CatecholHCID 962WaterHCID 3024DibromomethaneHCID 677643-Fluorocatechol

Product 1

HCID 157672604-Fluorobenzo[d][1,3]dioxole

Reagents, catalysts & solvents 3

HCID 21218Trioctylmethylammonium chlorideCatalystHCID 6344DichloromethaneSolventHCID 14798Sodium HydroxideSolvent

Procedure

Alliquat 336 (methyltrioctylammonium chloride, 0.63 g, 1.6 mmol), dibromomethane (40.7 g, 234.2 mmol) and water (31 mL) were placed in a 500 mL 3-necked flask equipped with an addition funnel, condenser and a stir bar. The addition funnel was charged with a solution of 3-fluorocatechol (20.0 g, 160 mmol) in 5M sodium hydroxide (80 mL). The mixture in the flask was heated to reflux and the solution of the catechol was added dropwise with good stirring over 2 hours and the resulting dark mixture heated an additional 2 hours at reflux. After cooling to room temperature, the reaction was diluted with methylene chloride and the layers separated. The aqueous layer was extracted with methylene chloride and the combined organic layers dried (Na2SO4 with charcoal). Filtration and concentration to a constant weight on the rota-vap gave 1-fluoro-2,3-methylenedioxybenzene (14.6 g, 104.2 mmol) as a dark yellow oil: 1H NMR (CDCl3); 6.80 (m, 1H), 6.68 (m, 2H), 6.04 (s, 2H).

Workup

  1. customequipped with an addition funnel, condenser and a stir bar
  2. temperatureThe mixture in the flask was heated
  3. temperatureto reflux
  4. temperaturethe resulting dark mixture heated an additional 2 hours
  5. temperatureat reflux
  6. customthe layers separated
  7. extractionThe aqueous layer was extracted with methylene chloride
  8. dry with materialthe combined organic layers dried (Na2SO4 with charcoal)
  9. filtrationFiltration and concentration to a constant weight on the rota-vap

Sources & evidence

ORD record
ord-04314cbb4c7b43d4aaafbf6f282a03e9
Source dataset
uspto-grants-2008_01
Patent number
US07314849B2

Reaction notes

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