Methanol → 3-styryl-1H-indazol-5-ol

HRID 1726050Notes

Reaction equation

HRID 1726050 reaction equation
C([O:8][C:9]1[CH:10]=[C:11]2[C:15](=[CH:16][CH:17]=1)[NH:14][N:13]=[C:12]2/[CH:18]=[CH:19]/[C:20]1[CH:25]=[CH:24][CH:23]=[CH:22][CH:21]=1)C1C=CC=CC=1.I[Si](C)(C)C.CO>C(#N)C.C(OCC)(=O)C>[CH:18]([C:12]1[C:11]2[C:15](=[CH:16][CH:17]=[C:9]([OH:8])[CH:10]=2)[NH:14][N:13]=1)=[CH:19][C:20]1[CH:21]=[CH:22][CH:23]=[CH:24][CH:25]=1

Participants

6

Reactant 3

HCID 887MethanolHCID 85247Trimethylsilyl iodide3×HCID 688442725-benzyloxy-3-((E)-styryl)-1H-indazole

Product 1

HCID 688387233-styryl-1H-indazol-5-olYield 56.2%

Reagents, catalysts & solvents 2

HCID 6342AcetonitrileSolventHCID 8857Ethyl AcetateSolvent

Conditions

Temperature
50 °C

Procedure

A solution of 652 mg of 5-benzyloxy-3-((E)-styryl)-1H-indazole in 60 ml of acetonitrile is stirred under argon. 1.13 ml of iodotrimethylsilane are added dropwise under an inert atmosphere. The suspension is stirred at approximately 50° C. for 3 hours and then at ambient temperature overnight. The medium is heated to around 50° C. and then 1.2 ml of iodotrimethylsilane are added. After stirring for 3 hours, 0.8 ml of iodotrimethylsilane is added. After stirring for approximately 4 hours, the medium is treated with 10 ml of methanol and stirred at ambient temperature for about fifteen minutes. The suspension is filtered through a paper filter and the filtrate is concentrated under vacuum in a rotary evaporator. The reaction crude is taken up in 50 ml of ethyl acetate and the organic phase is washed with 2×50 ml of a sodium thiosulfate solution, 2×50 ml of a saturated sodium bicarbonate solution, and 50 ml of a saturated sodium chloride solution. The organic phase is dried over magnesium sulfate and then concentrated under vacuum in a rotary evaporator. The reaction crude is purified by flash chromatography on silica (Varian 20 g cartridge), eluent: ethyl acetate/cyclohexane gradient 5:95 to 35:65 to obtain 265.4 mg of 3-styryl-1H-indazol-5-ol.

Workup

  1. customat ambient temperature
  2. customovernight
  3. temperatureThe medium is heated to around 50° C.
  4. stirringAfter stirring for 3 hours
  5. stirringAfter stirring for approximately 4 hours
  6. stirringstirred at ambient temperature for about fifteen minutes
  7. filtrationThe suspension is filtered through a paper
  8. filtrationfilter
  9. concentrationthe filtrate is concentrated under vacuum in a rotary evaporator
  10. customThe reaction crude
  11. washthe organic phase is washed with 2×50 ml of a sodium thiosulfate solution, 2×50 ml of a saturated sodium bicarbonate solution, and 50 ml of a saturated sodium chloride solution
  12. dry with materialThe organic phase is dried over magnesium sulfate
  13. concentrationconcentrated under vacuum in a rotary evaporator
  14. customThe reaction crude
  15. customis purified by flash chromatography on silica (Varian 20 g cartridge), eluent

Sources & evidence

ORD record
ord-4376f4e206934389b3ffdb3fc6fa8e4e
Source dataset
uspto-grants-2009_02
Patent number
US07491710B2

Reaction notes

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