Hydrochloric Acid → 9-Phenyl-9H-carbazole-3-boronic acid

HRID 1184050Notes

Reaction equation

HRID 1184050 reaction equation
Br[C:2]1[CH:3]=[CH:4][C:5]2[N:6]([C:15]3[CH:20]=[CH:19][CH:18]=[CH:17][CH:16]=3)[C:7]3[C:12]([C:13]=2[CH:14]=1)=[CH:11][CH:10]=[CH:9][CH:8]=3.C([Li])CCC.[B:26](OC)([O:29]C)[O:27]C.Cl>O1CCCC1>[C:7]1([N:6]2[C:5]3[CH:13]=[CH:14][C:2]([B:26]([OH:29])[OH:27])=[CH:3][C:4]=3[C:20]3[C:15]2=[CH:16][CH:17]=[CH:18][CH:19]=3)[CH:12]=[CH:11][CH:10]=[CH:9][CH:8]=1

Participants

6

Reactant 4

HCID 313Hydrochloric AcidHCID 8470Trimethyl borateHCID 189426243-Bromo-9-phenylcarbazole2×HCID 178418339Butyllithium

Product 1

HCID 513584509-Phenyl-9H-carbazole-3-boronic acidYield 86%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Conditions

Temperature
-80 °C

Procedure

10 g (31 mmol) of 3-bromo-9-phenyl-9H-carbazole was put into a 500 mL three-neck flask. The atmosphere in the flask was substituted with nitrogen. 150 mL of tetrahydrofuran (THF) was added to the three-neck flask and 3-bromo-9-phenyl-9H-carbazole was dissolved. The solution was cooled to −80° C. Into this solution, 20 mL (32 mmol) of n-butyllithium (1.58 mol/L hexane solution) was dropped with a syringe. After the dropping, the solution was stirred at the same temperature for one hour. After the stir, 3.8 mL (34 mmol) of trimethyl borate was added into the solution, and while the temperature of the solution was being increased to room temperature, the solution was stirred for about 15 hours. After the stir, about 150 mL of dilute hydrochloric acid (1.0 mol/L) was added to the solution and stirred for one hour. After the stir, an aqueous layer of the mixture was extracted with ethyl acetate and the extracted solution and an organic layer were washed together with a saturated sodium hydrogen carbonate aqueous solution. The organic layer was dried with magnesium sulfate, and then the mixture was naturally filtrated. The obtained filtrate was concentrated, so that a light-brown oily substance was obtained. The oily substance was dried with pressure reduced, so that 7.5 g of a light-brown solid substance, which was an object, was obtained in a yield of 86%. The synthesis scheme of Step 1 is shown in the following (C-1).

Workup

  1. dissolutionwas dissolved
  2. temperaturewhile the temperature of the solution was being increased to room temperature
  3. stirringthe solution was stirred for about 15 hours
  4. stirringstirred for one hour
  5. extractionAfter the stir, an aqueous layer of the mixture was extracted with ethyl acetate
  6. washthe extracted solution and an organic layer were washed together with a saturated sodium hydrogen carbonate aqueous solution
  7. dry with materialThe organic layer was dried with magnesium sulfate
  8. filtrationthe mixture was naturally filtrated
  9. concentrationThe obtained filtrate was concentrated, so that a light-brown oily substance
  10. customwas obtained
  11. customThe oily substance was dried with pressure
  12. customwas obtained in a yield of 86%
  13. customThe synthesis scheme of Step 1

Sources & evidence

ORD record
ord-3ab4c5059c024237b7ef7973b2fc4d98
Source dataset
uspto-grants-2014_03
Patent number
US08664849B2

Reaction notes

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