Trifluoroacetic acid → ethyl 5-amino-1-(2-fluorobenzyl)-1H-pyrazole-3-carboxylate

HRID 2212955Notes

Reaction equation

HRID 2212955 reaction equation
FC(F)(F)C(O)=O.[Na].[C:9]([CH2:11][C:12](=O)[C:13]([O:15][CH2:16][CH3:17])=[O:14])#[N:10].[F:19][C:20]1[CH:28]=[CH:27][CH:26]=[CH:25][C:21]=1[CH2:22][NH:23][NH2:24]>O1CCOCC1>[NH2:10][C:9]1[N:23]([CH2:22][C:21]2[CH:25]=[CH:26][CH:27]=[CH:28][C:20]=2[F:19])[N:24]=[C:12]([C:13]([O:15][CH2:16][CH3:17])=[O:14])[CH:11]=1

Participants

6

Reactant 4

HCID 6422Trifluoroacetic acidHCID 5360545SodiumHCID 10374537(2-Fluorobenzyl)hydrazineHCID 11309560Ethyl 3-cyano-2-oxopropanoate

Product 1

HCID 11391384ethyl 5-amino-1-(2-fluorobenzyl)-1H-pyrazole-3-carboxylate

Reagents, catalysts & solvents 1

HCID 312751,4-DioxaneSolvent

Procedure

111.75 g (75 ml, 0.98 mol) of trifluoroacetic acid are added to 100 g (0.613 mmol) of the sodium salt of ethyl cyanopyruvate (preparation in analogy to Borsche and Manteuffel, Liebigs Ann. 1934, 512, 97) in 2.5 l of dioxane under argon at room temperature with efficient stirring, and the mixture is stirred for 10 min, during which most of the precursor dissolves. Then 85.93 g (0.613 mol) of 2-fluorobenzylhydrazine are added and the mixture is boiled overnight. After cooling, the sodium trifluoroacetate crystals which have separated out are filtered off with suction and washed with dioxane, and the crude solution is reacted further.

Workup

  1. dissolutiondissolves
  2. waitthe mixture is boiled overnight
  3. temperatureAfter cooling
  4. customthe sodium trifluoroacetate crystals which have separated out
  5. filtrationare filtered off with suction
  6. washwashed with dioxane
  7. customthe crude solution is reacted further

Sources & evidence

ORD record
ord-c35603124da34fb8b80212cdd3399baf
Source dataset
uspto-grants-2006_09
Patent number
US07105523B2

Reaction notes

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