Carbon Dioxide → 1-Methyl-3-hydroxypyridine-2-one

Temperatur

140 °C

2,3-Dihydroxypyridine (5.55 g) is suspended in methyl iodide (20 ml) in a sealed tube and heated for 24 hours at 140° C. The reaction is taken to be complete when a dark brown residue forms as a separate phase from the methyl iodide and the tube is then cooled in solid carbon dioxide and opened. The excess methyl iodide is poured off, distilled water (10 ml) is added to the brown residue, and sulphur dioxide gas is bubbled through the mixture until the aqueous phase becomes clear. The pH of the reaction mixture is adjusted to a value of 6 with 1M aqueous sodium carbonate and the resulting solution then saturated with ammonium sulphate and extracted with chloroform until the chloroform layer no longer gives a blue colouration when added to ferric chloride solution. The chloroform extracts are combined and dried over sodium sulphate. The solvent is then evaporated under vacuum and the resulting residue is crystallised from petroleum ether (b.p. 100°-120° C.) using activated charcoal to give 3-hydroxy-1-methylpyrid-2-one, m.p. 129°-131° C.; νmax (nujol) 1,660, 3,100 cm-1 ; δ(d6DMSO) 3.6(s,3H), 6.1(t,1H), 6.8(m,2H), 7.3(s,1H); M+ 125.

1. distillationdistilled water (10 ml)
2. additionis added to the brown residue, and sulphur dioxide gas
3. customis bubbled through the mixture until the aqueous phase
4. extractionthe resulting solution then saturated with ammonium sulphate and extracted with chloroform until the chloroform layer
5. customno longer gives a blue colouration when
6. dry with materialdried over sodium sulphate
7. customThe solvent is then evaporated under vacuum
8. customthe resulting residue is crystallised from petroleum ether (b.p. 100°-120° C.)

ORD-Eintrag

ord-5a921b6deeae4f4f879e3391f0bc5a95

Quelldatensatz

uspto-grants-1985_10

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US04550101