Hydrazine hydrate (1:1) → HCID 22506888, compound

HRID 985430Notes

Reaction equation

HRID 985430 reaction equation
[C:1]([C:5]1[C:6](=[O:12])[O:7][CH:8]([CH3:11])[C:9]=1O)([CH3:4])([CH3:3])[CH3:2].O.[NH2:14][NH2:15]>C(O)C>[C:1]([C:5]1[C:6](=[O:12])[N:14]=[N:15][C:9]=1[CH:8]([OH:7])[CH3:11])([CH3:4])([CH3:3])[CH3:2]

Participants

4

Reactant 2

HCID 24654Hydrazine hydrate (1:1)HCID 54720230HCID 54720230, compound

Product 1

HCID 22506888HCID 22506888, compound

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

3-tert-Butyl-4-hydroxy-5-methyl-5H-furan-2-one (3 g, 17.7 mmol) was dissolved in ethanol (40 ml) with hydrazine hydrate (2.73 ml, 88.5 mmol) and heated under reflux for 14 h. The volume was reduced by evaporation to ˜15 ml and heating continued for a further 48 h. The solvents were removed under high vacuum and the residue was triturated with diethyl ether to leave a white solid (crude 4-tert-butyl-5-(1-hydroxyethyl)pyrazol-3-one, 2.6 g). This white solid (2.6 g, 14 mmol) was dissolved in dichloromethane (70 ml) with tosyl chloride (3.24 g, 16.8 mmol) then cooled to 0° C. and triethylamine (2.56 ml, 18.2 mmol) was added dropwise. The reaction mixture was allowed to warm to ambient temperature then diluted with more dichloromethane (50 ml) and washed with saturated brine (1×100 ml). The organic layer was dried (Na2SO4), filtered and concentrated under vacuum to leave a residue which was purified on silica gel using 20-50% ethyl acetate in isohexane as eluent to give 4-tert-butyl-5-(1-hydroxyethyl)-3-(4-methylphenyl)sulfonyloxypyrazole (3.8 g) as a white solid. 1H NMR (360 MHz, CDCl3) δ 1.34 (9H, s), 1.50 (3H, d, J=6.7 Hz), 2.45 (3H, s), 5.26 (1H, q, J=6.7 Hz), 7.35 (2H, d, J=8.2 Hz), 7.95 (2H, d, J=8.2 Hz), 10.72 (1H, br s); MS (ES+) m/e 339 [MH]+.

Workup

  1. temperatureheated
  2. temperatureunder reflux for 14 h
  3. customThe volume was reduced by evaporation to ˜15 ml
  4. temperatureheating
  5. customThe solvents were removed under high vacuum
  6. customthe residue was triturated with diethyl ether

Sources & evidence

ORD record
ord-cbaa26e8b1e44c66af587d7c97fd385d
Source dataset
uspto-grants-2005_03
Patent number
US06872720B2

Reaction notes

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