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

HRID 1750764Notes

Reaction equation

HRID 1750764 reaction equation
[CH3:1][C:2]1([CH3:13])[O:6][B:5]([OH:7])[C:4]2[CH:8]=[CH:9][C:10]([CH3:12])=[CH:11][C:3]1=2.C(OOC(=O)C1C=CC=CC=1)(=[O:21])C1C=CC=CC=1.C1C(=O)N(Br)C(=O)C1.C([O-])([O-])=O.[Na+].[Na+].Cl>C(Cl)(Cl)(Cl)Cl>[OH:7][B:5]1[C:4]2[CH:8]=[CH:9][C:10]([CH:12]=[O:21])=[CH:11][C:3]=2[C:2]([CH3:13])([CH3:1])[O:6]1

Participants

7

Reactant 5

HCID 313Hydrochloric AcidHCID 7187Benzoyl PeroxideHCID 10340Sodium CarbonateHCID 67184N-bromobutanimideHCID 768479533,3,5-Trimethylbenzo[c][1,2]oxaborol-1(3h)-ol

Product 1

HCID 768474911-Hydroxy-3,3-dimethyl-1,3-dihydrobenzo[c][1,2]oxaborole-5-carbaldehydeYield 412.8%

Reagents, catalysts & solvents 1

HCID 5943Carbon TetrachlorideSolvent

Procedure

To a solution of 3,3,5-trimethylbenzo[c][1,2]oxaborol-1(3H)-ol (27 mg, 0.153 mmol) in CCl4 (2 mL) at rt was added benzoyl peroxide (3.7 mg, 0.0153 mmol) followed by NBS (60 mg, 0.337 mmol). The reaction mixture was heated under reflux for 12 h, cooled to rt and treated with Na2CO3. The aqueous layer was acidified with 3 N HCl to pH of 3 and extracted with EA. The organic layer was washed with brine, dried over Na2SO4, filtered and concentrated under reduced pressure. The residue was purified by prep-TLC to give 1-hydroxy-3,3-dimethyl-1,3-dihydrobenzo[c][1,2]oxaborole-5-carbaldehyde (12 mg; yield 41%) as white solid. 1H NMR (400 MHz, CDCl3): δ 10.12 (s, 1 H), 7.88 (s, 2 H), 7.80 (s, 1 H), 1.62 (s,6 H) ppm.

Workup

  1. temperatureThe reaction mixture was heated
  2. temperatureunder reflux for 12 h
  3. extractionextracted with EA
  4. washThe organic layer was washed with brine
  5. dry with materialdried over Na2SO4
  6. filtrationfiltered
  7. concentrationconcentrated under reduced pressure
  8. customThe residue was purified by prep-TLC

Sources & evidence

ORD record
ord-33ab561c8e53464ca2f48087b161047d
Source dataset
uspto-grants-2015_10
Patent number
US09156860B2

Reaction notes

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