3,4-dihydro-2H-pyran → HCID 131727353, compound

HRID 1783961Notes

Reaction equation

HRID 1783961 reaction equation
[Br:1][C:2]1[CH:3]=[N:4][NH:5][C:6]=1[C:7]([CH3:15])([CH3:14])[O:8][SiH2:9][C:10]([CH3:13])([CH3:12])[CH3:11].[O:16]1[CH:21]=[CH:20][CH2:19][CH2:18][CH2:17]1.[H-].[Na+]>C(O)(C(F)(F)F)=O>[Br:1][C:2]1[C:6]([C:7]([CH3:15])([CH3:14])[O:8][SiH2:9][C:10]([CH3:13])([CH3:12])[CH3:11])=[N:5][N:4]([CH:17]2[CH2:18][CH2:19][CH2:20][CH2:21][O:16]2)[CH:3]=1.[Br:1][C:2]1[CH:3]=[N:4][N:5]([CH:17]2[CH2:18][CH2:19][CH2:20][CH2:21][O:16]2)[C:6]=1[C:7]([CH3:15])([CH3:14])[O:8][SiH2:9][C:10]([CH3:13])([CH3:12])[CH3:11]

Participants

6

Reactant 3

HCID 80803,4-dihydro-2H-pyranHCID 24758Sodium hydrideHCID 131727351HCID 131727351, compound

Product 2

HCID 131727352HCID 131727352, compoundHCID 131727353HCID 131727353, compoundYield 111.8%

Reagents, catalysts & solvents 1

HCID 6422Trifluoroacetic acidCatalyst

Conditions

Temperature
90 °C

Procedure

4-Bromo-5-(tert-butyl-dimethyl-silanyloxymethyl)-1H-pyrazole (1 g, 3.45 mmol) is dissolved in 3,4-dihydro-2H-pyran (0.944 mL, 10.34 mmol) in the presence of a catalytic amount of TFA (0.0026 mL, 0.035 mmol). The reaction mixture is stirred at 90° C. for 18 hours, cooled and then quenched using NaH (4.69 mg, 0.206 mmol). After removing the solvent, the residue is purified by silica gel column chromatography eluting with a mixture of 95:5 petroleum ether-ethyl acetate, followed by 90:10 petroleum ether-ethyl acetate. The fractions containing the desired compounds are collected and concentrated in vacuo to afford 4-bromo-3-(tert-butyl-dimethyl-silanyloxymethyl)-1-(tetrahydro-pyran-2-yl)-1H-pyrazole and 4-bromo-5-(tert-butyl-dimethyl-silanyloxymethyl)-1-(tetrahydro-pyran-2-yl)-1H-pyrazole (724 mg, 56%).

Workup

  1. temperaturecooled
  2. customquenched
  3. customAfter removing the solvent
  4. customthe residue is purified by silica gel column chromatography
  5. washeluting with a mixture of 95:5 petroleum ether-ethyl acetate
  6. additionThe fractions containing the desired compounds
  7. customare collected
  8. concentrationconcentrated in vacuo

Sources & evidence

ORD record
ord-b51b16d24d9643aebecc23fbf8993b4b
Source dataset
uspto-grants-2009_03
Patent number
US07501411B2

Reaction notes

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