Malonic Acid → N,N'-dibutyl-5-acetyl-thiobarbituric acid

HRID 443599

Reaktionsgleichung

[CH2:1]([NH:5][C:6]([NH:8][CH2:9][CH2:10][CH2:11][CH3:12])=[S:7])[CH2:2][CH2:3][CH3:4].[C:13](O)(=[O:18])[CH2:14][C:15](O)=[O:16].C(O[C:24](=[O:26])[CH3:25])(=O)C.O>C(O)(=O)C>[CH2:9]([N:8]1[C:13](=[O:18])[CH:14]([C:24](=[O:26])[CH3:25])[C:15](=[O:16])[N:5]([CH2:1][CH2:2][CH2:3][CH3:4])[C:6]1=[S:7])[CH2:10][CH2:11][CH3:12]

Komponenten

Reaktionsbedingungen

Temperatur: 70 °C

Versuchsvorschrift

358 g of N,N'-dibutylthiourea and 225 g of malonic acid are dissolved in 850 ml of glacial acetic acid, with warming, 190 ml of acetic anhydride are added dropwise at 60° C., with stirring, the mixture is warmed at 70° C. for 2 hours, 100 ml of acetic anhydride are added dropwise, the resulting mixture is warmed at 70° C. for 1 hour, a further 100 ml of acetic anhydride are added dropwise, the resulting mixture is warmed at 90° C. for 3 hours and 70 ml of water are added dropwise at 60°-90° C. The solvent is distilled off in vacuo at 50°-90° C. and the residue is stirred with 1 l of methanol. The crystalline precipitate is filtered off, washed with methanol and dried in vacuo at 40° C. 212 g of N,N'-dibutyl-5-acetyl-thiobarbituric acid are obtained.

Aufarbeitung

temperaturewith warming
temperaturethe resulting mixture is warmed at 70° C. for 1 hour
temperaturethe resulting mixture is warmed at 90° C. for 3 hours
distillationThe solvent is distilled off in vacuo at 50°-90° C.
stirringthe residue is stirred with 1 l of methanol
filtrationThe crystalline precipitate is filtered off
washwashed with methanol
customdried in vacuo at 40° C

Quellen und Nachweise

ORD-Eintrag: ord-56cef7ca5512402fb22179d415151dff
Quelldatensatz: uspto-grants-1981_04
DOI: 10.6084/m9.figshare.5104873.v1
Patentnummer: US04260776

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