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

HRID 1037075Notes

Reaction equation

HRID 1037075 reaction equation
[CH3:1][C:2]1([CH3:13])[O:6][B:5]([OH:7])[C:4]2[CH:8]=[C:9]([CH3:12])[CH:10]=[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]=[C:9]([CH:12]=[O:21])[CH:10]=[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 866854553,3,6-trimethylbenzo[c][1,2]oxaborol-1(3H)-ol

Product 1

HCID 866854601-Hydroxy-3,3-dimethyl-1,3-dihydrobenzo[c][1,2]oxaborole-6-carbaldehydeYield 654.5%

Reagents, catalysts & solvents 1

HCID 5943Carbon TetrachlorideSolvent

Procedure

To a solution of 3,3,6-trimethylbenzo[c][1,2]oxaborol-1(3H)-ol (6.87 g, 39 mmol) in CCl4 (100 mL) at rt was added benzoyl peroxide (0.944 g, 3.9 mmol) followed by NBS (13.9 g, 78 mmol). The reaction mixture was refluxed 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 EA. The organic layer was washed with brine, dried over Na2SO4, filtered and concentrated under reduced pressure. The residue was purified by column chromatography over silica gel eluted with DCM-MeOH (20:1) to give 1-hydroxy-3,3-dimethyl-1,3-dihydrobenzo[c][1,2]oxaborole-6-carbaldehyde (4.85 g; yield 65.4%) as a pale yellow solid. 1H NMR (500 MHz, CDCl3) δ 10.06 (s, 1H), 8.15 (s, 1H), 8.01 (d, J=8.0 Hz, 1 H), 7.42 (d, J=8.0 Hz, 1 H), 1.58 (s, 6H) ppm. MS: m/z=191.1 (M+1, ESI+).

Workup

  1. temperatureThe reaction mixture was refluxed for 16 h
  2. extractionextracted with EA
  3. washThe organic layer was washed with brine
  4. dry with materialdried over Na2SO4
  5. filtrationfiltered
  6. concentrationconcentrated under reduced pressure
  7. customThe residue was purified by column chromatography over silica gel
  8. washeluted with DCM-MeOH (20:1)

Sources & evidence

ORD record
ord-4fe2bb330c214575942991c411a7f42a
Source dataset
uspto-grants-2013_10
Patent number
US08546357B2

Reaction notes

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