Reaktion #63700

Reaktionsgleichung

water

1-[2,4-dichloro-5-(1-methylethoxy)phenyl]-3,3-dimethyl-1,2,4-triazolidin-5-one

pyruvic acid

pyruvic acid

→

2-[2,4-dichloro-5-(1-methylethoxy)phenyl]-6-methyl-1,2,4-triazine-3,5(2H,4H)-dione

Ausbeute 58.6%

Lösungsmittel

p-dioxane

Reaktionsbedingungen

Aufarbeitung

1. 1
   TemperaturThe mixture was heated at 90° C. for three hours
2. 2
   ExtraktionThe mixture was extracted with ethyl acetate
3. 3
   Sonstigethe solvent was evaporated from the
4. 4
   Extraktionextract under reduced pressure
5. 5
   Sonstigeto give an oil
6. 6
   SonstigeThe oil was purified by thin-layer preparative chromatography on silica gel
7. 7
   Wascheneluting with ethyl acetate:heptane (1:1)
8. 8
   ExtraktionExtraction of the appropriate bands

Vorschrift

To a stirred mixture of 1.0 g (0.0031 mole) of 1-[2,4-dichloro-5-(1-methylethoxy)phenyl]-3,3-dimethyl-1,2,4-triazolidin-5-one in 10 mL of p-dioxane was added 0.29 g (0.0031 mole) of pyruvic acid and one drop of concentrated sulfuric acid. The mixture was stirred at room temperature for one hour, then an additional 0.25 g (0.0029 mole) of pyruvic acid was added. The mixture was heated at 90° C. for three hours, then poured into water. The mixture was extracted with ethyl acetate, and the solvent was evaporated from the extract under reduced pressure to give an oil. The oil was purified by thin-layer preparative chromatography on silica gel, eluting with ethyl acetate:heptane (1:1). Extraction of the appropriate bands gave 0.6 g of 2-[2,4-dichloro-5-(1-methylethoxy)phenyl]-6-methyl-1,2,4-triazine-3,5(2H,4H)-dione as a solid (mp 163°-164° C.), Compound 10 in the tables.

Quelle