3,4-dihydro-2H-pyran → HCID 178516157, compound

HRID 1735006Notes

Reaction equation

HRID 1735006 reaction equation
[F:1][C:2]([F:10])([F:9])[C:3]1[CH:7]=[C:6]([OH:8])[NH:5][N:4]=1.[O:11]1[CH:16]=[CH:15][CH2:14][CH2:13][CH2:12]1>C(OCC)(=O)C.O.C1(C)C=CC(S(O)(=O)=O)=CC=1>[O:11]1[CH2:16][CH2:15][CH2:14][CH2:13][CH:12]1[N:5]1[C:6]([OH:8])=[CH:7][C:3]([C:2]([F:10])([F:9])[F:1])=[N:4]1

Participants

5

Reactant 2

HCID 80803,4-dihydro-2H-pyranHCID 178516162HCID 178516162, compound

Product 1

HCID 178516157HCID 178516157, compoundYield 76.7%

Reagents, catalysts & solvents 2

HCID 521998p-Toluenesulfonic acid monohydrateCatalystHCID 8857Ethyl AcetateSolvent2×

Conditions

Temperature
50 °C

Procedure

3-(Trifluoromethyl)-1H-pyrazol-5-ol (5.0 g, 0.032 mole) which is known in the art and p-toluene-sulfonic acid monohydrate (0.08 g) were dissolved in ethyl acetate (30 mL) and warmed to 50° C. 3,4-Dihydro-2H-pyran (2.9 g, 0.034 mole) was slowly added over a 10 minute period. After stirring 30 minutes at 50° C., the mixture was cooled and diluted with 100 mL of ethyl acetate. This solution was washed twice with 0.5% hydrochloric acid solution, then dried with magnesium sulfate, filtered and concentrated in vacuo. The residue was treated with 5 mL of ethyl acetate and 20 mL hexanes and filtered to give 1-(tetrahydro-2H-pyran-2-yl)-3-(trifluoromethyl)-1H-pyrazol-5-ol (5.8 g, 76% yield) as a white solid, mp=129°-130° C.

Workup

  1. temperaturethe mixture was cooled
  2. washThis solution was washed twice with 0.5% hydrochloric acid solution
  3. dry with materialdried with magnesium sulfate
  4. filtrationfiltered
  5. concentrationconcentrated in vacuo
  6. additionThe residue was treated with 5 mL of ethyl acetate and 20 mL hexanes
  7. filtrationfiltered

Sources & evidence

ORD record
ord-7300d717b2174532926c5ad7058295d7
Source dataset
uspto-grants-1996_07
Patent number
US05536701

Reaction notes

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