Ethanol → 5-(4-ethoxyphenyl)-1H-pyrazol-3-amine

HRID 654597Notes

Reaction equation

HRID 654597 reaction equation
C(O[C:4]1[CH:14]=[CH:13][C:7]([C:8]([CH2:10][C:11]#[N:12])=O)=[CH:6][CH:5]=1)C.O.[NH2:16][NH2:17].[CH2:18]([OH:20])[CH3:19]>>[CH2:18]([O:20][C:4]1[CH:5]=[CH:6][C:7]([C:8]2[NH:17][N:16]=[C:11]([NH2:12])[CH:10]=2)=[CH:13][CH:14]=1)[CH3:19]

Participants

4

Reactant 3

HCID 702EthanolHCID 24654Hydrazine hydrate (1:1)HCID 222416953-(4-Ethoxyphenyl)-3-oxopropanenitrile

Product 1

HCID 27587695-(4-ethoxyphenyl)-1H-pyrazol-3-amineYield 71%

Procedure

A (21.1 g, 112 mmole) portion of p-ethoxy-benzoylacetonitrile from Part A hereinabove and hydrazine monohydrate (7.0 mL, 144 mmole) were combined in 95% ethanol (145 mL) and refluxed for two hours. After cooling, the solvent was evaporated under vacuum and the crystalline residue recrystallized from ethyl acetate (500 mL) to afford 16.14 g (71%) of the subtitled compound as fine white needles (m.p. 152°-156°). An analytical sample was prepared with a second recrystallization (m.p. 155°-157°). 1H NMR (DMSO d6, δ) 7.57 (d, 2H, J=9 Hz, o-phenyl), 6.93 (d, 2H, J=9 Hz, m-phenyl), 5.70 (bs, 1H, pyrazole N-H), 4.35 (bs, 2H, NH2), 4.03 (q, 2H, J=7 Hz), 1.34 (t, 3H, J=7 Hz); IR (mull) 3397, 3136, 1615; 1519, 1474 cm-1 ; UV (ethanol) λ-max(ε) 205(25000), 261(20500); MS m/e(rel. intens.) 203 (M+, 100), 175, (90), 146 (35); Analysis calc'd for C11H13N3O=C, 65.01; H, 6.45; N, 20.67; found=C, 64.73; H, 6.77; N, 20.59; TLC (silica, 15% MeOH/CHCl3) Rf=0.50.

Workup

  1. temperaturerefluxed for two hours
  2. temperatureAfter cooling
  3. customthe solvent was evaporated under vacuum
  4. customthe crystalline residue recrystallized from ethyl acetate (500 mL)

Sources & evidence

ORD record
ord-ec4406e0258b4d2bb71b3ee299b25408
Source dataset
uspto-grants-1992_07
Patent number
US05132424

Reaction notes

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