Hydrazine hydrate (1:1) → HCID 178515597, compound

HRID 2182810Notes

Reaction equation

HRID 2182810 reaction equation
[Cl:1][C:2]1[CH:7]=[C:6]([Cl:8])[CH:5]=[CH:4][C:3]=1[C:9](=O)[CH2:10][C:11]([O:13]C)=O.O.[NH2:17][NH2:18]>C(O)C>[Cl:1][C:2]1[CH:7]=[C:6]([Cl:8])[CH:5]=[CH:4][C:3]=1[C:9]1[CH:10]=[C:11]([OH:13])[NH:18][N:17]=1

Participants

4

Reactant 2

HCID 24654Hydrazine hydrate (1:1)HCID 2758178Methyl 3-(2,4-dichlorophenyl)-3-oxopropanoate

Product 1

HCID 178515597HCID 178515597, compoundYield 79.4%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

970 g of methyl 3-(2,4-dichlorophenyl)-3-oxopropionate were initially charged in 4000 ml of ethanol. Over a period of 15 min, 201 g of hydrazine hydrate were added dropwise, the mixture was stirred at room temperature overnight, the precipitated solid was filtered off and the filtrate was concentrated to ⅓ of its original volume. The filtrate was stirred for another two nights, the resulting solid was filtered off with suction and the filtrate was again concentrated to ⅓ of its original volume. This gave a total of 714.2 g (79.4%) of 3-(2,4-dichlorophenyl)-5-hydroxy-1H-pyrazole as a colorless solid. M.p.: 198° C.

Workup

  1. filtrationthe precipitated solid was filtered off
  2. concentrationthe filtrate was concentrated
  3. stirringThe filtrate was stirred for another two nights
  4. filtrationthe resulting solid was filtered off with suction
  5. concentrationthe filtrate was again concentrated

Sources & evidence

ORD record
ord-a8803a72fbbd4cc6931c2e25f163882e
Source dataset
uspto-grants-2005_05
Patent number
US06897322B2

Reaction notes

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