Reaktion #5869

Reaktionsgleichung

1-(2,2-dimethyl-tetralin-1-yl)-5-imidazolecarboxylic acid methyl ester

sodium hydroxide

→

1-(2,2-dimethyl-4-oxo-tetralin-1-yl)-5-imidazolecarboxylic acid methyl ester

Ausbeute 28.2%

Lösungsmittel

water

Reaktionsbedingungen

Aufarbeitung

1. 1
   TemperaturThe suspension is heated to +87° C.
2. 2
   workup.ADDITIONwithin a period of 1.5 hours a total of 335 g of ammoniaperoxodisulfate is added portionwise in such a manner
3. 3
   Sonstigedoes not exceed +90° C
4. 4
   TemperaturAfter cooling the reaction mixture to +15° C.
5. 5
   ExtraktionThe mixture is extracted with 500 ml of methylene chloride
6. 6
   SonstigeThe organic phase is separated
7. 7
   Trocknendried with sodium sulfate
8. 8
   workup.ADDITIONtreated with activated carbon
9. 9
   Einengenconcentrated
10. 10
    SonstigeCrystallisation of the residue from diethyl ether

Vorschrift

142 g of 1-(2,2-dimethyl-tetralin-1-yl)-5-imidazolecarboxylic acid methyl ester are dispersed in 1 liter of deionisized water. The suspension is heated to +87° C., and within a period of 1.5 hours a total of 335 g of ammoniaperoxodisulfate is added portionwise in such a manner, that the temperature does not exceed +90° C. After cooling the reaction mixture to +15° C., the pH-value is adjusted to pH 4 by addition of 335 g of a sodium hydroxide solution 30%. The mixture is extracted with 500 ml of methylene chloride. The organic phase is separated, dried with sodium sulfate, treated with activated carbon and concentrated. Crystallisation of the residue from diethyl ether yields 42 g of 1-(2,2-dimethyl-4-oxo-tetralin-1-yl)-5-imidazolecarboxylic acid methyl ester, having a melting point of 93°-95° C.

Quelle