Sodium Carbonate → 4-Phenyl-1-(triphenylmethyl)-1H-pyrazole

HRID 1093775Notes

Reaction equation

HRID 1093775 reaction equation
C([O-])([O-])=O.[Na+].[Na+].I[C:8]1[CH:9]=[N:10][N:11]([C:13]([C:26]2[CH:31]=[CH:30][CH:29]=[CH:28][CH:27]=2)([C:20]2[CH:25]=[CH:24][CH:23]=[CH:22][CH:21]=2)[C:14]2[CH:19]=[CH:18][CH:17]=[CH:16][CH:15]=2)[CH:12]=1.[C:32]1(B(O)O)[CH:37]=[CH:36][CH:35]=[CH:34][CH:33]=1>C1(C)C=CC=CC=1.O.O.C1C=CC([P]([Pd]([P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)([P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)[P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)=CC=1>[C:32]1([C:8]2[CH:9]=[N:10][N:11]([C:13]([C:26]3[CH:31]=[CH:30][CH:29]=[CH:28][CH:27]=3)([C:20]3[CH:25]=[CH:24][CH:23]=[CH:22][CH:21]=3)[C:14]3[CH:19]=[CH:18][CH:17]=[CH:16][CH:15]=3)[CH:12]=2)[CH:37]=[CH:36][CH:35]=[CH:34][CH:33]=1

Participants

7

Reactant 3

HCID 10340Sodium CarbonateHCID 66827Phenylboronic AcidHCID 153244794-Iodo-1-(triphenylmethyl)-1H-pyrazole

Product 1

HCID 595596204-Phenyl-1-(triphenylmethyl)-1H-pyrazoleYield 59.6%

Reagents, catalysts & solvents 3

HCID 178418397HCID 178418397, compoundCatalystHCID 962WaterSolventHCID 22272177Toluene waterSolvent

Procedure

Trityl chloride (1.58 g, 5.67 mmol) was added to a stirred cold (0-5° C.) solution of 4-iodo pyrazole (1 g, 5.15 mmol) and triethylamine (1.04 g, 10.3 mmol) in DCM (12 mL). Stirring was continued at room temperature overnight. Cold water was then added and the product was extracted with DCM and the organic layer was washed with saturated sodium bicarbonate solution followed by brine. The organic phase collected was dried over Na2SO4 and concentrated under reduced pressure The residue was purified by column chromatography (using neutral alumina and 2% EtOAc in hexane as eluent) to afford 1.9 g (84.4% Yield) of 4-iodo-1-trityl-1H-pyrazole. Na2CO3 (727 mg, 6.86 mmol) was added to a stirred solution of 4-iodo-1-trityl-1H-pyrazole (1.5 g, 3.43 mmol) in toluene: H2O (4:1, 20 mL). Pd(PPh3)4 (790 mg, 0.686 mmol) and phenylboronic acid (838 mg, 6.86 mmol) were then added and the reaction mixture was heated to reflux for 2 hrs. The reaction mixture was then diluted with water and the product was extracted with ethyl acetate. The organic layer was washed with saturated brine solution, dried over sodium sulfate and concentrated to in vacuo. Purification by column chromatography (using neutral alumina and 5% EtOAc in hexane as eluent) afforded 790 mg (59.4% Yield) of 4-phenyl-1-trityl-1H-pyrazole. 1H NMR (300 MHz, CDCl3): δ 7.96-7.94 (s, 1H), 7.64-7.6 (s, 1H), 7.46-7.4 (d, 2H), 7.36-7.0 (m, 11H), 7.24-7.16 (m, 7H). A solution of 4-phenyl-1-trityl-1H-pyrazole (785 mg, 2.03 mmol) in ether.HCl (15 mL) was stirred for 1 hr. The reaction mixture was then concentrated under reduced pressure and washed with hexane to afford 320 mg (87.4% Yield) of 4-phenyl-1H-pyrazole hydrochloride. 1H NMR (300 MHz, DMSO-d6): δ 8.1-8.08 (s, 2H), 7.64 (d, 2H), 7.38 (t, 2H), 7.22 (t, 1H).

Workup

  1. temperaturethe reaction mixture was heated
  2. temperatureto reflux for 2 hrs
  3. extractionthe product was extracted with ethyl acetate
  4. washThe organic layer was washed with saturated brine solution
  5. dry with materialdried over sodium sulfate
  6. concentrationconcentrated to in vacuo
  7. customPurification by column chromatography (using neutral alumina and 5% EtOAc in hexane as eluent)

Sources & evidence

ORD record
ord-6235f3afe719468992fc869f86424b79
Source dataset
uspto-grants-2012_03
Patent number
US08129376B2

Reaction notes

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