Hydrochloric Acid → Albendazole

HRID 261896

Reaktionsgleichung

Reaktionsgleichung von HRID 261896
[N:1]#[C:2]N.Cl[C:5]([O:7][CH3:8])=[O:6].[OH-].[Na+].Cl.[CH2:12]([S:15][C:16]1[CH:21]=[CH:20][C:19]([NH2:22])=[C:18]([NH2:23])[CH:17]=1)[CH2:13][CH3:14]>O.CO>[CH2:12]([S:15][C:16]1[CH:21]=[CH:20][C:19]2[N:22]=[C:2]([NH:1][C:5]([O:7][CH3:8])=[O:6])[NH:23][C:18]=2[CH:17]=1)[CH2:13][CH3:14]

Komponenten

8

Edukt 5

HCID 313Hydrochloric Acid2×HCID 6586Methyl chloroformateHCID 9864CyanamideHCID 14798Sodium HydroxideHCID 30170844-(Propylthio)benzene-1,2-diamine

Produkt 1

HCID 2082Albendazole

Reagenzien, Katalysatoren, Lösungsmittel 2

HCID 887MethanolLösungsmittelHCID 962WaterLösungsmittel3×

Reaktionsbedingungen

Temperatur
50 °C

Versuchsvorschrift

Preparation of methyl 5-propylthio-2-benzimidazole carbamate--A 1.82 g portion of cyanamide was dissolved in 10 ml of water. Methyl chloroformate, 4.64 g, and 6.34 g of 50% aqueous sodium hydroxide in 6 ml of water were added simultaneously so as to maintain the pH at approximately 7 as determined by a pH meter. The reaction mixture was stirred at 50° C. for one hour. A portion of 7.4 g of concentrated hydrochloric acid in 7 ml of water was added until the pH was 4. The methanol solution of 4-propylthio-o-phenylenediamine from Example IV was added at once. More of the hydrochloric acid solution was added to adjust the pH to 4. The reaction mixture was heated to distill the methanol. As methanol was nearly removed more hydrochloric acid solution was added to keep the pH at 4. Water was added from time to time to keep the slurry from becoming too thick. The reaction slurry was heated at 100° C. for one hour after the methanol had been removed. The reaction slurry was cooled, filtered and washed liberally with water. The solids were air dried to produce 8.77 g of crude methyl 5-propylthio-2-benzimidazole carbamate. The crude solids were washed 3 times with cold acetone and dried to produce 7.52 g of product assaying 97% methyl-5-propylthio-2-benzimidazole carbamate by HPLC, 73% yield from the 4-propylthio-2-nitroaniline employed in Example IV.

Aufarbeitung

  1. temperatureto maintain the pH at approximately 7
  2. temperatureThe reaction mixture was heated
  3. distillationto distill the methanol
  4. customAs methanol was nearly removed more hydrochloric acid solution
  5. additionwas added
  6. additionWater was added from time to time
  7. temperatureThe reaction slurry was heated at 100° C. for one hour after the methanol
  8. customhad been removed
  9. temperatureThe reaction slurry was cooled
  10. filtrationfiltered
  11. washwashed liberally with water
  12. customdried

Quellen und Nachweise

ORD-Eintrag
ord-5c65760cded345e7878fe56986be3995
Quelldatensatz
uspto-grants-1979_05
Patentnummer
US04152522

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