Chloroform → ethyl 5-amino-1-(4-chlorophenyl)-1H-pyrazole-4-carboxylate

HRID 1419691Notes

Reaction equation

HRID 1419691 reaction equation
C(O[CH:4]=[C:5]([C:11]#[N:12])[C:6]([O:8][CH2:9][CH3:10])=[O:7])C.Cl.[Cl:14][C:15]1[CH:20]=[CH:19][C:18]([NH:21][NH2:22])=[CH:17][CH:16]=1.C(Cl)(Cl)Cl>C(O)C>[NH2:12][C:11]1[N:21]([C:18]2[CH:19]=[CH:20][C:15]([Cl:14])=[CH:16][CH:17]=2)[N:22]=[CH:4][C:5]=1[C:6]([O:8][CH2:9][CH3:10])=[O:7]

Participants

5

Reactant 3

HCID 6212ChloroformHCID 71600Hydrazine, (4-chlorophenyl)-, hydrochloride (1:1)HCID 789432-Propenoic acid, 2-cyano-3-ethoxy-, ethyl ester

Product 1

HCID 4101804ethyl 5-amino-1-(4-chlorophenyl)-1H-pyrazole-4-carboxylateYield 48%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

A solution of ethyl ethoxymethylenecyanoacetate (3 g, 17.7 mmol) and 4-chlorophenylhydrazine hydrochloride (3.33 g, 18.6 mmol) in ethanol (60 mL) was refluxed for 2 days, following the procedure described in Schmidt, P. et al. Helv.Chim.Acta, 1959, 349. The reaction mixture was then allowed to cool to room temperature, whereupon a precipitate was formed. Cold CHCl3 was added, the precipitate was filtered and washed with more CHCl3. The filtrate and the washings were evaporated to dryness, precipitated with ether, filtered and dried to give ethyl 5-amino-1-(4-chlorophenyl)-1H-pyrazole-4-carboxylate (2.25 g, 48%) as a white solid: mp 150°-156° C.; 1H NMR (80 MHz, CDCl3) δ (TMS) 7.77 (s, 1H, pyrazole), 7.48 (s, 4H, arom), 4.30 (q, J=7, 2H, OCH2), 1.36 (t, J=7, 3H, OCH2CH3). Analysis calculated for C12H12ClN3O2 : C 54.25; H 4.55; N 15.81. Found: C 54.77; H 4.49; N 15.65.

Workup

  1. customwas formed
  2. filtrationthe precipitate was filtered
  3. washwashed with more CHCl3
  4. customThe filtrate and the washings were evaporated to dryness
  5. customprecipitated with ether
  6. filtrationfiltered
  7. customdried

Sources & evidence

ORD record
ord-ad548d99a90e4284a18690d849adb848
Source dataset
uspto-grants-1999_03
Patent number
US05888941

Reaction notes

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