Sulfuric Acid → HCID 178493795, Verbindung

HRID 267949Notizen

Reaktionsgleichung

Reaktionsgleichung von HRID 267949
N[C:2]1[C:7]([O:8][CH3:9])=[N:6][C:5]([O:10][CH3:11])=[CH:4][N:3]=1.S(=O)(=O)(O)[OH:13].N([O-])=O.[Na+].NC(N)=O>O>[OH:13][C:2]1[C:7]([O:8][CH3:9])=[N:6][C:5]([O:10][CH3:11])=[CH:4][N:3]=1

Komponenten

6

Edukt 4

HCID 1118Sulfuric AcidHCID 1176UreaHCID 205289233,5-Dimethoxypyrazin-2-amineHCID 23668193Sodium Nitrite

Produkt 1

HCID 178493795HCID 178493795, Verbindung

Reagenzien, Katalysatoren, Lösungsmittel 1

HCID 962WaterLösungsmittel

Reaktionsbedingungen

Temperatur
60 °C

Versuchsvorschrift

A solution of 2-amino-3,5-dimethoxypyrazine (0.02 mole) in 300 ml. of 6M sulfuric acid at 0°-5° C. is treated with 0.022 mole sodium nitrite in 25 ml. of water at such a rate to insure that the termperature of the reaction mixture does not rise above 5° C. After standing 45 minutes at 0°-5°C., a little urea is added to destroy excess nitrous acid and the mixture then is treated with sodium hydroxide solution until strongly basic. The reaction mixture is warmed to 60° C. for 1 hour and then brought to pH 8.5. The mixture is concentrated to a third of the original volume and cooled in the refrigerator overnight. The product is separated by filtration and dried in vacuo, recrystallized from a suitable solvent to give 2-hydroxy-3,5-dimethoxypyrazine.

Aufarbeitung

  1. customdoes not rise above 5° C
  2. customto destroy excess nitrous acid
  3. additionthe mixture then is treated with sodium hydroxide solution until strongly basic
  4. concentrationThe mixture is concentrated to a third of the original volume
  5. temperaturecooled in the refrigerator overnight
  6. customThe product is separated by filtration
  7. customdried in vacuo
  8. customrecrystallized from a suitable solvent

Quellen und Nachweise

ORD-Eintrag
ord-07f334ff719a488aa0a15740cf0d40b2
Quelldatensatz
uspto-grants-1976_03
Patentnummer
US03946009

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