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

HRID 1076702

Reaktionsgleichung

Reaktionsgleichung von HRID 1076702
[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

Edukt 3

HCID 6101p-Toluenesulfonic acidHCID 278451HCID 278451, VerbindungHCID 3016950(1-(3,4-Dichlorophenyl)ethyl)hydrazine

Produkt 1

HCID 141513883-Amino-1-(alpha-methyl-3,4-dichlorobenzyl)-pyrazol-5-one

Reagenzien, Katalysatoren, Lösungsmittel 2

HCID 702EthanolLösungsmittel2×HCID 6344DichloromethaneLösungsmittel

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 2 hours and standing overnight, the reaction solution was concentrated as far as possibile 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 possibile
  3. customon 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-eec9294e3b5a4eb093af9940bac6c7cc
Quelldatensatz
uspto-grants-1976_05
Patentnummer
US03957814

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