Trimethyl borate → HCID 66953917, compound

HRID 495025Notes

Reaction equation

HRID 495025 reaction equation
[F:1][C:2]1[CH:7]=[CH:6][CH:5]=[C:4]2[O:8][CH2:9][O:10][C:3]=12.C([Li])CCC.C[O:17][B:18](OC)[O:19]C>C1COCC1>[F:1][C:2]1([B:18]([OH:19])[OH:17])[CH:7]=[CH:6][CH:5]=[C:4]2[O:8][CH2:9][O:10][CH:3]12

Participants

5

Reactant 3

HCID 8470Trimethyl borateHCID 157672604-Fluorobenzo[d][1,3]dioxoleHCID 178418339Butyllithium

Product 1

HCID 66953917HCID 66953917, compoundYield 21.3%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Conditions

Temperature
-65 °C

Procedure

1-Fluoro-2,3-methylenedioxybenzene (5.0 g, 35.7 mmol) was dissolved in THF (70 mL) and the solution was cooled to −65° C. in a dry ice acetone bath. n-Butyl lithium (2.5 g, 15.7 mL, 39.3 mmol) was added to the solution via syringe with stirring. The reaction was allowed to warm to −35° C. over 1 hour, then cooled to −65° C. and treated with trimethylborate (4.1 g, 39.3 mmol) via syringe. The reaction was allowed to warm slowly to room temperature, quenched with 1N HCl (50 mL), stirred for 15 minutes, and then extracted with ether. The organic phase was then extracted with 1N sodium hydroxide and this aqueous extract was then acidified with 1N hydrochloric acid. The acidic aqueous solution was then extracted with two portions of ether and these combined ether extracts were dried and concentrated to an oily solid that was triturated with methylene chloride. The resulting solid was collected by filtration, washed with methylene chloride, and dried to give 1-fluoro-2,3-methylenedioxyphenylboronic acid (1.4 g, 7.6 mmol) as a tan solid: 1H NMR (DMSO-d6): δ 8.05 (br s, 2H), 7.08 (dd, 1H, J=7.8, 5.1 Hz), 6.76 (d, 1H, J=7.8 Hz), 6.08 (s, 2H).

Workup

  1. temperatureto warm to −35° C. over 1 hour
  2. temperaturecooled to −65° C.
  3. temperatureto warm slowly to room temperature
  4. customquenched with 1N HCl (50 mL)
  5. stirringstirred for 15 minutes
  6. extractionextracted with ether
  7. extractionThe organic phase was then extracted with 1N sodium hydroxide
  8. extractionthis aqueous extract
  9. extractionThe acidic aqueous solution was then extracted with two portions of ether
  10. dry with materialthese combined ether extracts were dried
  11. concentrationconcentrated to an oily solid
  12. customthat was triturated with methylene chloride
  13. filtrationThe resulting solid was collected by filtration
  14. washwashed with methylene chloride
  15. customdried

Sources & evidence

ORD record
ord-b71b69700f0b47f0ad698a4f6714edba
Source dataset
uspto-grants-2009_05
Patent number
US07538214B2

Reaction notes

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