Perchloric Acid → ethyl 2-[1-benzyl-5-(3,4-dihydro-2H-1-benzopyran-6-yl)-3-(trifluoromethyl)-1H-pyrazol-4-yl]-2-(tert-butoxy)acetate

HRID 591080Notes

Reaction equation

HRID 591080 reaction equation
[CH2:1]([N:8]1[C:12]([C:13]2[CH:14]=[CH:15][C:16]3[O:21][CH2:20][CH2:19][CH2:18][C:17]=3[CH:22]=2)=[C:11]([CH:23]([OH:29])[C:24]([O:26][CH2:27][CH3:28])=[O:25])[C:10]([C:30]([F:33])([F:32])[F:31])=[N:9]1)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.Cl(O)(=O)(=O)=O>C(OC(C)(C)C)(=O)C>[CH2:1]([N:8]1[C:12]([C:13]2[CH:14]=[CH:15][C:16]3[O:21][CH2:20][CH2:19][CH2:18][C:17]=3[CH:22]=2)=[C:11]([CH:23]([O:29][C:2]([CH3:7])([CH3:3])[CH3:1])[C:24]([O:26][CH2:27][CH3:28])=[O:25])[C:10]([C:30]([F:32])([F:31])[F:33])=[N:9]1)[C:2]1[CH:3]=[CH:4][CH:5]=[CH:6][CH:7]=1

Participants

4

Reactant 2

HCID 24247Perchloric AcidHCID 70855451ethyl 2-[1-benzyl-5-(3,4-dihydro-2H-1-benzopyran-6-yl)-3-(trifluoromethyl)-1H-pyrazol-4-yl]-2-hydroxyacetate

Product 1

HCID 70855195ethyl 2-[1-benzyl-5-(3,4-dihydro-2H-1-benzopyran-6-yl)-3-(trifluoromethyl)-1H-pyrazol-4-yl]-2-(tert-butoxy)acetateYield 52.6%

Reagents, catalysts & solvents 1

HCID 10908tert-Butyl acetateSolvent

Procedure

To a solution of ethyl 2-[1-benzyl-5-(3,4-dihydro-2H-1-benzopyran-6-yl)-3-(trifluoromethyl)-1H-pyrazol-4-yl]-2-hydroxyacetate (49f) (70 mg, 0.152 mmol) in tert-butyl acetate (2.9 mL) at 0° C. was added perchloric acid (0.347 mL). The mixture was stirred for 1 hour at room temperature before being slowly quenched with a saturated solution of potassium carbonate (10 mL). The layers were separated and the aqueous layer was extracted with ethyl acetate (2×10 mL). The organic layers were dried over sodium sulfate and concentrated in vacuo. The residue was purified by preparative TLC (cyclohexane/ethyl acetate 75/25) to provide the desired ether (49g) (22 mg, 0.04 mmol, 28%) as a clear yellow oil.

Workup

  1. custombefore being slowly quenched with a saturated solution of potassium carbonate (10 mL)
  2. customThe layers were separated
  3. extractionthe aqueous layer was extracted with ethyl acetate (2×10 mL)
  4. dry with materialThe organic layers were dried over sodium sulfate
  5. concentrationconcentrated in vacuo
  6. customThe residue was purified by preparative TLC (cyclohexane/ethyl acetate 75/25)

Sources & evidence

ORD record
ord-cec0ccbe155f441a880f4116ae05fa13
Source dataset
uspto-grants-2016_01
Patent number
US09238026B2

Reaction notes

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