Hydrochloric Acid → (5-(9H-carbazol-9-yl)pyridin-3-yl)boronic acid

HRID 520827Notes

Reaction equation

HRID 520827 reaction equation
Br[C:2]1[CH:3]=[C:4]([N:8]2[C:20]3[CH:19]=[CH:18][CH:17]=[CH:16][C:15]=3[C:14]3[C:9]2=[CH:10][CH:11]=[CH:12][CH:13]=3)[CH:5]=[N:6][CH:7]=1.[Li]C(C)(C)C.C[O:27][B:28](OC)[O:29]C.Cl>C1COCC1>[CH:19]1[C:20]2[N:8]([C:4]3[CH:3]=[C:2]([B:28]([OH:29])[OH:27])[CH:7]=[N:6][CH:5]=3)[C:9]3[C:14](=[CH:13][CH:12]=[CH:11][CH:10]=3)[C:15]=2[CH:16]=[CH:17][CH:18]=1

Participants

6

Reactant 4

HCID 313Hydrochloric AcidHCID 8470Trimethyl borateHCID 594495909-(5-bromopyridin-3-yl)-9H-carbazoleHCID 178418306HCID 178418306, compound

Product 1

HCID 86679311(5-(9H-carbazol-9-yl)pyridin-3-yl)boronic acid

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

To a solution of 9-(5-bromopyridin-3-yl)-9H-carbazole (2B) (1.7 g, 5.3 mmol) in THF (20 mL) was added a solution of tert-BuLi (1.7M in hexanes, 6.8 mL, 11.6 mmol) at about −78° C. The crude mixture was then stirred at about −78° C. for about 40 min, then a freshly distilled trimethylborate (0.89 mL, 8 mmol) was added. The resulting solution was stirred at RT overnight, then a 5% HCl aqueous solution (50 mL) was added and the whole was stirred for about 20 hours. The mixture was extracted with ethyl acetate (250 mL) three times, the organic phase was collected; dried over Na2SO4, concentrated and recrystallized with hexanes/dichloromethane to give product 2C, a light yellow solid (0.9 g, 60% yield).

Workup

  1. stirringthe whole was stirred for about 20 hours
  2. extractionThe mixture was extracted with ethyl acetate (250 mL) three times
  3. customthe organic phase was collected
  4. dry with materialdried over Na2SO4
  5. concentrationconcentrated
  6. customrecrystallized with hexanes/dichloromethane

Sources & evidence

ORD record
ord-57d29e89699346f1b304b561ca699844
Source dataset
uspto-grants-2016_05
Patent number
US09328094B2

Reaction notes

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