Methylhydrazine → 5-tert-Butyl-4-methoxy-2-methyl-2H-pyrazole-3-carboxylic acid ethyl ester

HRID 1481510Notes

Reaction equation

HRID 1481510 reaction equation
FC(F)(F)C(OI(C1C=CC=CC=1)O[C:8](=[O:13])C(F)(F)F)=O.B(F)(F)F.CCOCC.[CH3:31][CH2:32][O:33][C:34]([C:36]([CH2:38][C:39]([C:41]([CH3:44])([CH3:43])[CH3:42])=O)=O)=[O:35].[CH3:45][NH:46][NH2:47]>CO>[CH2:32]([O:33][C:34]([C:36]1[N:46]([CH3:45])[N:47]=[C:39]([C:41]([CH3:42])([CH3:43])[CH3:44])[C:38]=1[O:13][CH3:8])=[O:35])[CH3:31]

Participants

6

Reactant 4

HCID 6061MethylhydrazineHCID 8000Boron trifluoride etherateHCID 83403Ethyl 5,5-dimethyl-2,4-dioxohexanoateHCID 102317Bis(trifluoroacetoxy)iodobenzene

Product 1

HCID 674117235-tert-Butyl-4-methoxy-2-methyl-2H-pyrazole-3-carboxylic acid ethyl ester

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

[Bis(trifluoroacetoxy)iodo]benzene (430 mg, 1.00 mmol) was dissolved in anhydrous MeOH (4 mL), the resulting solution was stirred at room temperature for 3 min. BF3.OEt2 (0.123 mL, 1.00 mmol) was then added via syringe. Ethyl trimethylacetopyruvate (200 mg, 1.00 mmol) was added dropwise via syringe and the resulting mixture was stirred at room temperature for 12 h. The solvent was removed under reduced pressure and the resulting residue was dissolved in dry EtOH (2 mL). CH3NHNH2 (52.6 μL, 1.00 mmol) was added via syringe and the resulting mixture was stirred at 80° C. for 8 h. The solvent was removed under reduced pressure and the resulting residue was chromatographed on a 24-g SiO2 pre-packed column eluting with 0:1-3:7 EtOAc/hexanes to yield 5-tert-butyl-4-methoxy-2-methyl-2H-pyrazole-3-carboxylic acid ethyl ester. 1H-NMR (400 MHz, CDCl3) δ: 4.39 (q, J=7.1 Hz, 2H), 4.03 (s, 3H), 3.83 (s, 3H), 1.42 (t, J=7.2 Hz, 3H), 1.34 (s, 9H).

Workup

  1. stirringthe resulting mixture was stirred at room temperature for 12 h
  2. customThe solvent was removed under reduced pressure
  3. dissolutionthe resulting residue was dissolved in dry EtOH (2 mL)
  4. stirringthe resulting mixture was stirred at 80° C. for 8 h
  5. customThe solvent was removed under reduced pressure
  6. customthe resulting residue was chromatographed on a 24-g SiO2 pre-packed column
  7. washeluting with 0:1-3:7 EtOAc/hexanes

Sources & evidence

ORD record
ord-0353aa018c9f41fc88a96c84b8bab025
Source dataset
uspto-grants-2016_08
Patent number
US09409915B2

Reaction notes

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