Water → 4-(4-chloro-benzylsulfanyl)-3,5-dimethyl-1H-pyrazole

HRID 1797134Notes

Reaction equation

HRID 1797134 reaction equation
[Cl:1][C:2]1[CH:16]=[CH:15][C:5]([CH2:6][S:7][CH:8]([C:12](=O)[CH3:13])[C:9](=O)[CH3:10])=[CH:4][CH:3]=1.O.[NH2:18][NH2:19].O>C(O)C.O.C1(C)C=CC(S(O)(=O)=O)=CC=1>[Cl:1][C:2]1[CH:16]=[CH:15][C:5]([CH2:6][S:7][C:8]2[C:12]([CH3:13])=[N:18][NH:19][C:9]=2[CH3:10])=[CH:4][CH:3]=1

Participants

6

Reactant 3

HCID 962WaterHCID 24654Hydrazine hydrate (1:1)HCID 221748613-(4-Chloro-benzylsulfanyl)-pentane-2,4-dione

Product 1

HCID 221748524-(4-chloro-benzylsulfanyl)-3,5-dimethyl-1H-pyrazoleYield 72%

Reagents, catalysts & solvents 2

HCID 521998p-Toluenesulfonic acid monohydrateCatalystHCID 702EthanolSolvent

Procedure

To a solution of crude 3-(4-chloro-benzylsulfanyl)-pentane-2,4-dione [prepared as described above from 3-chloro-pentan-2,3-dione (1.03 g, 7.63 mmol) and 4-chlorobenzyl mercaptan (1.21 g, 7.63 mmol)] in ethanol (60 mL) was added hydrazine hydrate (0.713 mL, 22.9 mmol) and p-toluenesulfonic acid monohydrate (ca. 25 mg). The solution was heated to reflux and stirred for 15 hours. The reaction mixture was allowed to cool to room temperature, and water (300 mL) was added. The precipitate that formed was removed by filtration, washed with water, and dried to provide 1.38 g (72%) of the product as a white solid: 1H NMR (CDCl3) δ 7.17 (d, J=8.4 Hz, 2H), 6.92 (d, J=8.4 Hz, 2H), 3.57 (s, 2H), and 2.02 (s, 6H) ppm. 13C NMR (CDCl3) δ 137.2, 132.7, 130.3, 128.3, 105.2, 39.9, 10.7 ppm.

Workup

  1. temperatureThe solution was heated
  2. temperatureto reflux
  3. customThe precipitate that formed
  4. customwas removed by filtration
  5. washwashed with water
  6. customdried

Sources & evidence

ORD record
ord-7853a5884ad1498a849305931e26e942
Source dataset
uspto-grants-2006_04
Patent number
US07034031B2

Reaction notes

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