Ethanol → Ethyl 5-(propan-2-yl)-1H-pyrazole-3-carboxylate

HRID 1409976Notes

Reaction equation

HRID 1409976 reaction equation
[CH:1]([C:4]1[CH:8]=[C:7]([C:9]([OH:11])=[O:10])[NH:6][N:5]=1)([CH3:3])[CH3:2].[CH2:12](O)[CH3:13].C(Cl)(=O)C>C1C=CC=CC=1>[CH:1]([C:4]1[CH:8]=[C:7]([C:9]([O:11][CH2:12][CH3:13])=[O:10])[NH:6][N:5]=1)([CH3:3])[CH3:2]

Participants

5

Reactant 3

HCID 702EthanolHCID 6367Acetyl chlorideHCID 178439321HCID 178439321, compound

Product 1

HCID 6422484Ethyl 5-(propan-2-yl)-1H-pyrazole-3-carboxylate

Reagents, catalysts & solvents 1

HCID 241BenzeneSolvent

Procedure

To a clean round bottom flask equipped with a stir bar, Dean-Stark trap, and reflux condenser was added 3-isopropyl-1H-pyrazole-5-carboxylic acid (1 gram, 6.49 mmol, purchased from Fisher Scientific). 30 mL of ethanol (95%, purchased from Fisher Scientific) was added followed by 30 mL of benzene. 43 μL of acetyl chloride was then added and the solution refluxed over the three days. The solvent was then removed using a Buchi rotoevaporator. The residue was then taken up in ethyl acetate and washed with NaHCO3 (saturated). It was then dried with sodium sulfate, filtered and concentrated. Purification using a Teledyne ISCO silica chromatography (hexanes/ethyl acetate gradient) afforded the desired ester. Yield, 85% 1H-NMR δ 6.7 (s, 1H), 5.1 (bs, NH), 4.41 (q, 2H), 3.13 (septet, 1H), 1.38 (t, 3H), 1.33 (d, 6H).

Workup

  1. customTo a clean round bottom flask equipped with a stir bar
  2. temperatureDean-Stark trap, and reflux condenser
  3. temperaturethe solution refluxed over the three days
  4. customThe solvent was then removed
  5. washwashed with NaHCO3 (saturated)
  6. dry with materialIt was then dried with sodium sulfate
  7. filtrationfiltered
  8. concentrationconcentrated
  9. customPurification

Sources & evidence

ORD record
ord-a9e3967f4f1849dc8f7d1697f7cbdf3d
Source dataset
uspto-grants-2014_12
Patent number
US08921401B2

Reaction notes

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