p-Toluenesulfonic acid → 3-Amino-1-(alpha-methyl-3,4-dichlorobenzyl)-pyrazol-5-one

HRID 1415591

Reaktionsgleichung

Reaktionsgleichung von HRID 1415591
[CH3:1][CH:2]([NH:11][NH2:12])[C:3]1[CH:8]=[CH:7][C:6]([Cl:9])=[C:5]([Cl:10])[CH:4]=1.C([O:15][C:16](=O)[CH:17]=[C:18]([NH2:22])OCC)C.C1(C)C=CC(S(O)(=O)=O)=CC=1>C(O)C.C(Cl)Cl>[NH2:22][C:18]1[NH:12][N:11]([CH:2]([CH3:1])[C:3]2[CH:8]=[CH:7][C:6]([Cl:9])=[C:5]([Cl:10])[CH:4]=2)[C:16](=[O:15])[CH:17]=1

Komponenten

6

Versuchsvorschrift

41 g of α-methyl-3,4-dichlorobenzylhydrazine, dissolved in absolute ethanol, were added dropwise to a solution of 31.8 g of β-amino-β-ethoxyacrylic acid ethyl ester and 1.5 g of p-toluenesulphonic acid in 150 ml of ethanol at room temperature under nitrogen gas. After stirring for two hours and standing overnight, the reaction solution was concentrated as far as possible on a rotary evaporator. The residue which remained was dissolved in 2 N sodium hydroxide solution. Any unconverted starting products or by-products were extracted with ether. The aqueous phase was then brought to pH 5 with acetic acid. The oil thereby produced was taken up in methylene chloride and the organic phase was dried over Na2SO4. After evaporating off the solvent, the reaction product crystallized out. It was recrystallized from methanol. Melting point 127°-129° C; yield 21 g (38.5% of theory).

Aufarbeitung

  1. waitstanding overnight
  2. concentrationthe reaction solution was concentrated as far as
  3. custompossible on a rotary evaporator
  4. dissolutionThe residue which remained was dissolved in 2 N sodium hydroxide solution
  5. extractionwere extracted with ether
  6. customThe oil thereby produced
  7. dry with materialthe organic phase was dried over Na2SO4
  8. customAfter evaporating off the solvent
  9. customthe reaction product crystallized out
  10. customIt was recrystallized from methanol

Quellen und Nachweise

ORD-Eintrag
ord-b8b77edeb0ba4dc6a6fe68ba7950f5db
Quelldatensatz
uspto-grants-1977_01
Patentnummer
US04005215

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