Ethanol → Ethyl 1-tert-butyl-5-methyl-1H-pyrazole-3-carboxylate

HRID 1098591Notes

Reaction equation

HRID 1098591 reaction equation
Cl.[C:2]([NH:6][NH2:7])([CH3:5])([CH3:4])[CH3:3].C([C:11](=[C:17]=[CH:18]N(C)C)[C:12]([O:14][CH2:15][CH3:16])=[O:13])(=O)C.[CH2:22](O)C>CCOCC>[C:2]([N:6]1[C:18]([CH3:22])=[CH:17][C:11]([C:12]([O:14][CH2:15][CH3:16])=[O:13])=[N:7]1)([CH3:5])([CH3:4])[CH3:3]

Participants

5

Reactant 3

HCID 702EthanolHCID 81889tert-Butylhydrazine monohydrochlorideHCID 86623854HCID 86623854, compound

Product 1

HCID 2800557Ethyl 1-tert-butyl-5-methyl-1H-pyrazole-3-carboxylateYield 45%

Reagents, catalysts & solvents 1

HCID 3283Diethyl EtherSolvent

Procedure

In ethanol (5 mL) was placed the t-butylhydrazine hydrochloride (0.79 g, 6.3 mmol) and ethyl 2-acetyl-3-(dimethylaminomethylene)acrylate (1.0 g, 6.3 mmol). The mixture was refluxed for 8 hours. The mix was evaporated at reduced pressure to give an oil. The oil was dissolved in ether (25 mL) and washed successively with water (25 mL), saturated sodium bicarbonate (25 mL) and brine (25 mL) was dried (Na2SO4), concentrated in vacuo and purified by silica gel column chromatography (EtOAc/hexanes) to obtain ethyl 1-tert-butyl-5-methyl-1H-pyrazole-3-carboxylate (0.60 g, 45% yield). 1H NMR (400 MHz, DMSO-d6): δ 6.54 (s, 1H), 4.22 (q, J=7.2 Hz, 2H), 2.44 (s, 3H), 2.42 (s, 3H), 1.57 (s, 9H), 1.25 (t, J=7.2 Hz, 3H); MS (ESI) m/z: 211.1 (M+H+).

Workup

  1. temperatureThe mixture was refluxed for 8 hours
  2. customThe mix was evaporated at reduced pressure
  3. customto give an oil
  4. washwashed successively with water (25 mL), saturated sodium bicarbonate (25 mL) and brine (25 mL)
  5. dry with materialwas dried (Na2SO4)
  6. concentrationconcentrated in vacuo
  7. custompurified by silica gel column chromatography (EtOAc/hexanes)

Sources & evidence

ORD record
ord-2557e3d52995472496a22fc614158656
Source dataset
uspto-grants-2012_03
Patent number
US08143293B2

Reaction notes

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