Acetic Anhydride → HCID 58763934, compound

HRID 859196Notes

Reaction equation

HRID 859196 reaction equation
[Cl:1][C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][C:3]=1[N:8]1[C:12]([C:13]2[CH:18]=[CH:17][C:16]([Cl:19])=[CH:15][CH:14]=2)=[C:11]([OH:20])[C:10]([C:21]([OH:23])=[O:22])=[N:9]1.C(N(CC)C(C)C)(C)C.[C:33](OC(=O)C)(=[O:35])[CH3:34]>C(Cl)Cl>[C:33]([O:20][C:11]1[C:10]([C:21]([OH:23])=[O:22])=[N:9][N:8]([C:3]2[CH:4]=[CH:5][CH:6]=[CH:7][C:2]=2[Cl:1])[C:12]=1[C:13]1[CH:18]=[CH:17][C:16]([Cl:19])=[CH:15][CH:14]=1)(=[O:35])[CH3:34]

Participants

5

Reactant 3

HCID 7918Acetic AnhydrideHCID 81531DiisopropylethylamineHCID 58763932HCID 58763932, compound

Product 1

HCID 58763934HCID 58763934, compound

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

1-(2-Chlorophenyl)-5-(4-chlorophenyl)-4-hydroxy-1H-pyrazole-3-carboxylic acid I-6c (572.0 g, 1.64 mol) was combined with 8 liters of methylene chloride to give an off-white suspension. N,N-Diisopropylethylamine (427.9 g, 3.29 mol) was added over 15 minutes while keeping the temperature between 20–25° C. A clear yellow solution resulted. Acetic anhydride (334.5 g, 3.24 mol) was added over 5 minutes keeping the temperature between 20–25° C. The reaction was stirred at room temperature for 16 hours. The crude reaction solution was washed twice with 4 liters portions of 0.5 M citric acid and once with 4 liters of brine. The crude solution was concentrated in vacuo to a total volume of 1 liter. This milky suspension was then added to 4 liters of hexanes causing the desired product to precipitate instantly. The solids were granulated for 30 minutes and then collected by filtration. The filtercake was rinsed with 3 liters of hexanes and then air-dried for 16 hours. The isolated product was then further dried at 60° C. and 8 mm for 2 hours. 4-Acetoxy-1-(2-chlorophenyl)-5-(4-chlorophenyl)-1H-pyrazole-3-carboxylic acid I-6d (601.6 g, 94%) was isolated as a powdery, off-white solid.

Workup

  1. customto give an off-white suspension
  2. custombetween 20–25° C
  3. customA clear yellow solution resulted
  4. custombetween 20–25° C
  5. customThe crude reaction solution
  6. washwas washed twice with 4 liters portions of 0.5 M citric acid and once with 4 liters of brine
  7. concentrationThe crude solution was concentrated in vacuo to a total volume of 1 liter
  8. additionThis milky suspension was then added to 4 liters of hexanes causing the desired product
  9. customto precipitate instantly
  10. waitThe solids were granulated for 30 minutes
  11. filtrationcollected by filtration
  12. washThe filtercake was rinsed with 3 liters of hexanes
  13. customair-dried for 16 hours
  14. customThe isolated product was then further dried at 60° C.
  15. wait8 mm for 2 hours
  16. custom(601.6 g, 94%) was isolated as a powdery, off-white solid

Sources & evidence

ORD record
ord-569ede5a70e045958dfb51b48d159ada
Source dataset
uspto-grants-2006_12
Patent number
US07151097B2

Reaction notes

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