Hydrazine hydrate (1:1) → 5-[2-(4-Chlorophenyl)-ethyl]-1H-pyrazole-3-carboxylic acid ethyl ester

HRID 1366923Notes

Reaction equation

HRID 1366923 reaction equation
O.[NH2:2][NH2:3].[CH2:4]([O:6][C:7](=[O:22])[C:8](=O)[CH2:9][C:10](=O)[CH2:11][CH2:12][C:13]1[CH:18]=[CH:17][C:16]([Cl:19])=[CH:15][CH:14]=1)[CH3:5]>CCO>[CH2:4]([O:6][C:7]([C:8]1[CH:9]=[C:10]([CH2:11][CH2:12][C:13]2[CH:18]=[CH:17][C:16]([Cl:19])=[CH:15][CH:14]=2)[NH:3][N:2]=1)=[O:22])[CH3:5]

Participants

4

Reactant 2

HCID 24654Hydrazine hydrate (1:1)HCID 574351006-(4-chlorophenyl)-2,4-dioxohexanoic Acid Ethyl Ester

Product 1

HCID 574351015-[2-(4-Chlorophenyl)-ethyl]-1H-pyrazole-3-carboxylic acid ethyl esterYield 52.8%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

Hydrazine hydrate (0.300 mL, 6.18 mmol) was added to a stirring room temperature solution of 67 (0.1.7484 g, 6.18 mmol) in EtOH (6.2 mL, 1 M) under N2. The reaction was then heated to reflux until judged complete by HPLC (40 min): Upon cooling, a white crystalline solid precipitated from the reaction. The solid was separated by filtration, washed with EtOH, and dried to obtain pure 68 (0.9092 g, 52.7%): 1H (CDCl3, 300 MHz): δ 12.44 (1H, broad s), 7.21 (2H, d, J=8.3 Hz), 7.08 (2H, d, J=8.1 Hz), 6.58 (1H, s), 4.33 (2H, q, J=7.0 Hz), 3.00 (2H, t, J=7.0 Hz), 2.93 (2H, t, J=7.0 Hz), 1.33 (3H, t, J=7.0 Hz) ppm. Partial 13C (CDCl3, 75 MHz): δ 139.12, 131.93, 129.67, 128.50, 106.49, 60.94, 34.72, 14.20 ppm. HPLC: 10.269 min.

Workup

  1. temperatureThe reaction was then heated
  2. temperatureto reflux
  3. customuntil judged complete by HPLC (40 min)
  4. temperatureUpon cooling
  5. customa white crystalline solid precipitated from the reaction
  6. customThe solid was separated by filtration
  7. washwashed with EtOH
  8. customdried

Sources & evidence

ORD record
ord-6ab6a4f3a8064681bffa4dbcb9a5cc9f
Source dataset
uspto-grants-2011_02
Patent number
US07893098B2

Reaction notes

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