Reaktion #65124

Reaktionsgleichung

bromine

pyrimidine-2,4(1H,3H)-dione

water

pyrimidine-2,4(1H,3H)-dione

pyrimidine

→

5-hydroxyprimidine-2,4(1H,3H)-dione

Lösungsmittel

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturcooled
2. 2
   SonstigeThe resulting reaction mixture
3. 3
   Temperaturis refluxed
4. 4
   Sonstigethe solvent is removed
5. 5
   Sonstigethe residue is recrystallized from an appropriate solvent
6. 6
   Sonstigechromatographed over silica-gel

Vorschrift

According to the synthetic method shown in Scheme A, above, bromine is added dropwise to an ice-cooled solution or suspension of a pyrimidine-2,4(1H,3H)-dione derivative of formula (III) in water until the solution or suspension is colored pale yellow. The pyrimidine-2,4(1H,3H)-dione derivatives of formula (III) are prepared, for example, by the methods described in Heterocyclic Compounds 16, The pyrimidine supplement II, D. J. Brown, An Interscience Publication, John Willy & Sons, New York, 1985, Table LVIII, page 728. To the resulting pale yellow solution or suspension is added carefully an ice cold saturated aqueous NaHCO3 solution. The resulting reaction mixture is refluxed, the solvent is removed and the residue is recrystallized from an appropriate solvent or chromatographed over silica-gel to give a 5-hydroxyprimidine-2,4(1H,3H)-dione derivative of formula (IV).

Quelle