Hydrazine → (+/-)-4,5-Dihydro-3-(2-thienyl)-1H-pyrazole-5-carboxylic acid

HRID 126992

Reaktionsgleichung

Reaktionsgleichung von HRID 126992
[OH-].[K+].[S:3]1[CH:7]=[CH:6][CH:5]=[C:4]1[C:8](=O)/[CH:9]=[CH:10]/[C:11]([OH:13])=[O:12].[NH2:15][NH2:16]>CO>[S:3]1[CH:7]=[CH:6][CH:5]=[C:4]1[C:8]1[CH2:9][CH:10]([C:11]([OH:13])=[O:12])[NH:16][N:15]=1

Komponenten

5

Edukt 3

HCID 9321HydrazineHCID 14797Potassium HydroxideHCID 5773483trans-3-(2-Thenoyl)acrylic Acid

Produkt 1

HCID 20288723(+/-)-4,5-Dihydro-3-(2-thienyl)-1H-pyrazole-5-carboxylic acidAusbeute 82,6 %

Reagenzien, Katalysatoren, Lösungsmittel 1

HCID 887MethanolLösungsmittel

Versuchsvorschrift

Potassium hydroxide (3.3 g) is dissolved in 100 cc of methanol and 9.1 g of 4-(2-thienyl)-4-oxocrotonic acid is added. To the resulting solution is added 2 g of hydrazine and the solution is refluxed for 2 hours. The methanol is removed and the viscous residue dissolved in 80 cc of water. The solution is made strongly acid with 20% HCl and a precipitate forms. It is filtered and air-dried to yield 8.1 g of the title compound, melting point 163°-165° C., dec. After recrystallization from ethanol the compound is constant melting at 171°-173° C., dec.

Aufarbeitung

  1. temperaturethe solution is refluxed for 2 hours
  2. customThe methanol is removed
  3. dissolutionthe viscous residue dissolved in 80 cc of water
  4. filtrationIt is filtered
  5. customair-dried

Quellen und Nachweise

ORD-Eintrag
ord-4ac3de84c5a9464a8fb216246b539cf8
Quelldatensatz
uspto-grants-1981_03
Patentnummer
US04254267

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