Reaktion #54479

Reaktionsgleichung

sodium acetate

4-Amino-2-bromo-thiazole hydrobromide

trichloroacetyl chloride

pyridine

→

title compound

Ausbeute 53.9%

2-Bromo-4-trichloroacetamidothiazole

Ausbeute 53.9%

Lösungsmittel

methylene chloride

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturmaintaining
2. 2
   Sonstigereaction temperature at 0° C. with an ice bath
3. 3
   workup.ADDITIONthe addition
4. 4
   workup.STIRRINGthe reaction mixture was stirred at room temperature for 3 hours
5. 5
   workup.STIRRINGstirred for 30 minutes
6. 6
   SonstigeThe mixture was separated
7. 7
   Waschenthe organic layer washed with 2N hydrochloric acid, water, sodium carbonate solution and water
8. 8
   TrocknenThe organic layer was dried (MgSO4)
9. 9
   Sonstigethe solvent removed in vacuo
10. 10
    workup.ADDITIONthe residue treated with charcoal in hexane
11. 11
    Sonstigerecrystallised from hexane

Vorschrift

4-Amino-2-bromo-thiazole hydrobromide (15.6 g) and trichloroacetyl chloride (14.3 g) were suspended in methylene chloride (100 ml) with stirring and treated dropwise with pyridine (16 ml) over 15 minutes maintaining reaction temperature at 0° C. with an ice bath. After completing the addition, the reaction mixture was stirred at room temperature for 3 hours, then poured onto 20% aqueous sodium acetate (250 ml) and stirred for 30 minutes. The mixture was separated and the organic layer washed with 2N hydrochloric acid, water, sodium carbonate solution and water. The organic layer was dried (MgSO4) and the solvent removed in vacuo and the residue treated with charcoal in hexane and recrystallised from hexane to give the title compound (10.5 g) m.p. 77°-80° C. (Found: C, 19.0; H, 0.7; N, 8.5. C5H2Cl3BrN2OS requires C, 18.5; H, 0.6; N, 8.6%)

Quelle