Methylhydrazine → HCID 13370531, compound

HRID 1011894Notes

Reaction equation

HRID 1011894 reaction equation
[CH3:1][O:2][C:3](=[O:16])[C:4](=O)[CH2:5][C:6]([C:8]1[CH:13]=[CH:12][CH:11]=[C:10]([Br:14])[CH:9]=1)=O.[CH3:17][NH:18][NH2:19]>CCO>[CH3:1][O:2][C:3]([C:4]1[N:18]([CH3:17])[N:19]=[C:6]([C:8]2[CH:13]=[CH:12][CH:11]=[C:10]([Br:14])[CH:9]=2)[CH:5]=1)=[O:16].[CH3:1][O:2][C:3]([C:4]1[CH:5]=[C:6]([C:8]2[CH:13]=[CH:12][CH:11]=[C:10]([Br:14])[CH:9]=2)[N:18]([CH3:17])[N:19]=1)=[O:16]

Participants

5

Reactant 2

HCID 6061MethylhydrazineHCID 17024761Methyl 4-(3-bromophenyl)-2,4-dioxobutanoate

Product 2

HCID 13370531HCID 13370531, compoundYield 37%HCID 673157795-(3-bromo-phenyl)-1-methyl-1H-pyrazole-3-carboxylic acid methyl esterYield 28%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Conditions

Temperature
65 °C

Procedure

3.00 g (10.52 mmol) of 4-(3-bromo-phenyl)-2,4-dioxo-butyric acid methyl ester were suspended in 16 ml of EtOH and 0.485 g (10.52 mmol) of methylhydrazine were added. The reaction was heated under reflux (65° C.) for 5 h. Then the solvent was evaporated and the residue was partitioned between aqueous 1N HCl/EtOAc (3×). The organic phases were washed with aqueous sat. NaCl, dried (Na2SO4) and evaporated. The crude product was purified by flash chromatography (SiO2, n-heptane/EtOAc 99:1) to give 1.64 g (37%) of 5-(3-bromo-phenyl)-2-methyl-2H-pyrazole-3-carboxylic acid methyl ester (and ethyl ester) as white powder (MS: methyl ester 295.1 MH+, 1 Br; ethyl ester 309.1 MH+, 1 Br) and 1.11 g (28%) of 5-(3-bromo-phenyl)-1-methyl-1H-pyrazole-3-carboxylic acid methyl ester (and ethyl ester) as yellow oil (MS: methyl ester 295.1 MH+, 1 Br; ethyl ester 309.1 MH+, 1 Br).

Workup

  1. temperatureThe reaction was heated
  2. customThen the solvent was evaporated
  3. customthe residue was partitioned between aqueous 1N HCl/EtOAc (3×)
  4. washThe organic phases were washed with aqueous sat. NaCl
  5. dry with materialdried (Na2SO4)
  6. customevaporated
  7. customThe crude product was purified by flash chromatography (SiO2, n-heptane/EtOAc 99:1)

Sources & evidence

ORD record
ord-56ecabf6e1d7437ea20f71d052bc4285
Source dataset
uspto-grants-2011_07
Patent number
US07977358B2

Reaction notes

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