4-Bromophenylhydrazine → Ethyl 5-amino-1-(4-bromophenyl)-1H-pyrazole-4-carboxylate

HRID 2187399Notes

Reaction equation

HRID 2187399 reaction equation
[Br:1][C:2]1[CH:7]=[CH:6][C:5]([NH:8][NH2:9])=[CH:4][CH:3]=1.C(O[CH:13]=[C:14]([C:20]#[N:21])[C:15]([O:17][CH2:18][CH3:19])=[O:16])C>C(O)C.C(OCC)C>[CH2:18]([O:17][C:15]([C:14]1[CH:13]=[N:9][N:8]([C:5]2[CH:6]=[CH:7][C:2]([Br:1])=[CH:3][CH:4]=2)[C:20]=1[NH2:21])=[O:16])[CH3:19]

Participants

5

Reactant 2

HCID 121584-BromophenylhydrazineHCID 789432-Propenoic acid, 2-cyano-3-ethoxy-, ethyl ester

Product 1

HCID 4662659Ethyl 5-amino-1-(4-bromophenyl)-1H-pyrazole-4-carboxylateYield 70.2%

Reagents, catalysts & solvents 2

HCID 702EthanolSolventHCID 3283Diethyl EtherSolvent

Procedure

A solution of 4-bromophenylhydrazine (2.76 g, 14.7 mmol) and ethyl (ethoxymethylene)cyanoacetate (2.50 g, 14.8 mmol) in ethanol (15 mL) was heated at reflux for 2 hours. Upon cooling, a tan precipitate formed. The suspension was diluted with diethyl ether and suction filtered to remove solid. The filtercake was rinsed with diethyl ether and vacuum oven dried to afford 3.20 g (70%) of product as a tan solid: 1H NMR (CDCl3) d 7.79 (s, 1H), 7.64 (d, J=8.7 Hz, 2H), 7.45 (d, J=8.7 Hz, 2H), 5.30 (s, 2H), 4.31 (q, J=7.2 Hz, 2H), 1.37 (t, J=7.2 Hz, 3H) ppm.

Workup

  1. temperatureat reflux for 2 hours
  2. temperatureUpon cooling
  3. customa tan precipitate formed
  4. filtrationfiltered
  5. customto remove solid
  6. washThe filtercake was rinsed with diethyl ether and vacuum oven
  7. customdried

Sources & evidence

ORD record
ord-bf2b75cdd5a84f86a87b473cafbd9323
Source dataset
uspto-grants-2002_06
Patent number
US06410533B1

Reaction notes

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