Hydrochloric Acid → 6-Fluoro-1-hydroxy-3,3-dimethyl-1,3-dihydrobenzo[c][1,2]oxaborole-5-carbaldehyde

HRID 1750855Notes

Reaction equation

HRID 1750855 reaction equation
[F:1][C:2]1[C:3]([CH3:14])=[CH:4][C:5]2[C:9]([CH3:11])([CH3:10])[O:8][B:7]([OH:12])[C:6]=2[CH:13]=1.C(OOC(=O)C1C=CC=CC=1)(=[O:22])C1C=CC=CC=1.C1C(=O)N(Br)C(=O)C1.C([O-])([O-])=O.[Na+].[Na+].Cl>C(Cl)(Cl)(Cl)Cl>[F:1][C:2]1[C:3]([CH:14]=[O:22])=[CH:4][C:5]2[C:9]([CH3:10])([CH3:11])[O:8][B:7]([OH:12])[C:6]=2[CH:13]=1

Participants

7

Reactant 5

HCID 313Hydrochloric AcidHCID 7187Benzoyl PeroxideHCID 10340Sodium CarbonateHCID 67184N-bromobutanimideHCID 866850956-fluoro-3,3,5-trimethylbenzo[c][1,2]oxaborol-1(3H)-ol

Product 1

HCID 866850976-Fluoro-1-hydroxy-3,3-dimethyl-1,3-dihydrobenzo[c][1,2]oxaborole-5-carbaldehydeYield 908.7%

Reagents, catalysts & solvents 1

HCID 5943Carbon TetrachlorideSolvent

Procedure

To a solution of 6-fluoro-3,3,5-trimethylbenzo[c][1,2]oxaborol-1(3H)-ol (388 mg, 2 mmol) in CCl4 (60 mL) at rt was added benzoyl peroxide (48.4 mg, 0.2 mmol) followed by NBS (783 mg, 4.4 mmol). The reaction mixture was heated under reflux for 16 h, cooled to rt and treated with Na2CO3. The aqueous layer was acidified with 3 N HCl to pH of 3 and extracted with DCM (60 mL×3). The organic layer was dried over Na2SO4, filtered and concentrated under reduced pressure to give 6-fluoro-1-hydroxy-3,3-dimethyl-1,3-dihydrobenzo[c][1,2]oxaborole-5-carbaldehyde (378 mg, 91%) as a pale yellow solid. 1H NMR (500 MHz, CDCl3) δ 10.369 (s, 1H), 7.687 (d, J=5.5 Hz, 1H), 7.409 (d, J=8.0 Hz, 1H), 2.715 (s, 3H), 1.484 (s, 6H) ppm.

Workup

  1. temperatureThe reaction mixture was heated
  2. temperatureunder reflux for 16 h
  3. extractionextracted with DCM (60 mL×3)
  4. dry with materialThe organic layer was dried over Na2SO4
  5. filtrationfiltered
  6. concentrationconcentrated under reduced pressure

Sources & evidence

ORD record
ord-2fe8958d648249e789fa73ffbb86a22e
Source dataset
uspto-grants-2015_10
Patent number
US09156860B2

Reaction notes

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