Trifluoroacetic acid → 5-(3-chloro-benzylamino)-2-methyl-2H-pyrazole-3-carboxylic acid methyl ester

HRID 1952176Notes

Reaction equation

HRID 1952176 reaction equation
[CH3:1][O:2][C:3]([C:5]1[N:6]([CH3:11])[N:7]=[C:8]([NH2:10])[CH:9]=1)=[O:4].[Cl:12][C:13]1[CH:14]=[C:15]([CH:18]=[CH:19][CH:20]=1)[CH:16]=O.FC(F)(F)C(O)=O.C([SiH](CC)CC)C>C(#N)C>[CH3:1][O:2][C:3]([C:5]1[N:6]([CH3:11])[N:7]=[C:8]([NH:10][CH2:16][C:15]2[CH:18]=[CH:19][CH:20]=[C:13]([Cl:12])[CH:14]=2)[CH:9]=1)=[O:4]

Participants

6

Reactant 4

HCID 6422Trifluoroacetic acidHCID 114773-ChlorobenzaldehydeHCID 12052TriethylsilaneHCID 13248993methyl 3-amino-1-methyl-1H-pyrazole-5-carboxylate

Product 1

HCID 576194175-(3-chloro-benzylamino)-2-methyl-2H-pyrazole-3-carboxylic acid methyl ester

Reagents, catalysts & solvents 1

HCID 6342AcetonitrileSolvent

Procedure

5-Amino-2-methyl-2H-pyrazole-3-carboxylic acid methyl ester (644, 1.3 g, 8.0 mmol) was combined with 3-chlorobenzaldehyde (645, 0.95 mL, 8.4 mmol) and acetonitrile (40 mL). Trifluoroacetic acid (3.2 mL, 42.0 mmol) was added followed by triethylsilane (6.7 mL, 42.0 mmol). The reaction was heated to reflux overnight and then concentrated. Ethyl acetate was added and the solution was washed with 1N potassium carbonate. The organic portion was dried over anhydrous sodium sulfate, filtered and concentrated. The compound (646, 0.944 g, 42%) was crystallized from a mixture of ethyl acetate:hexane.

Workup

  1. temperatureThe reaction was heated
  2. temperatureto reflux overnight
  3. concentrationconcentrated
  4. additionEthyl acetate was added
  5. washthe solution was washed with 1N potassium carbonate
  6. dry with materialThe organic portion was dried over anhydrous sodium sulfate
  7. filtrationfiltered
  8. concentrationconcentrated
  9. customThe compound (646, 0.944 g, 42%) was crystallized from a mixture of ethyl acetate

Sources & evidence

ORD record
ord-98bb9bccb8274c6a802ee8ed9059f47c
Source dataset
uspto-grants-2013_03
Patent number
US08404700B2

Reaction notes

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