Reaktion #735754

Reaktionsgleichung

ethyl 5-acetyl-2-methylamino-4-thiazolecarboxylate

acetic acid

hydrogen bromide

acetic acid

pyridinium hydrobromide

→

ethyl 5-(2-bromoacetyl)-2-methylamino-4-thiazolecarboxylate

Lösungsmittel

water

Reaktionsbedingungen

Aufarbeitung

1. 1
   Filtrationthe precipitate was collected by filtration
2. 2
   workup.DISSOLUTIONThe precipitate was dissolved in a mixture of ethyl acetate and water
3. 3
   ExtraktionThe organic extracted
4. 4
   Waschenwas washed with brine
5. 5
   Trocknendried over magnesium sulfate
6. 6
   Sonstigeevaporated in vacuo
7. 7
   WaschenThe residue was washed with ethyl ether

Vorschrift

To a mixture of ethyl 5-acetyl-2-methylamino-4-thiazolecarboxylate (7.1 g), 30% acetic acid solution of hydrogen bromide (10 ml) and acetic acid (50 ml) was added pyridinium hydrobromide perbromide (9.9 g) at ambient temperature and stirred for 2.5 hours. The reaction mixture was poured into water (300 ml) and the precipitate was collected by filtration. The precipitate was dissolved in a mixture of ethyl acetate and water and the resultant mixture was adjusted to pH 7.0 with 20% aqueous potassium carbonate. The organic extracted was washed with brine, dried over magnesium sulfate and evaporated in vacuo. The residue was washed with ethyl ether to give ethyl 5-(2-bromoacetyl)-2-methylamino-4-thiazolecarboxylate (6.6 g). mp 130°-131.5° C.

Quelle