Reaktion #165684

Reaktionsgleichung

solution

4-bromo-2,2,5,5-tetramethyldihydrofuran-3(2H)-one

thiourea

triethylamine

→

title compound

4,4,6,6-tetramethyl-4,6-dihydrofuro[3,4-d]thiazol-2-amine

Lösungsmittel

ethanol

Reaktionsbedingungen

Aufarbeitung

1. 1
   TemperaturThe reaction mixture was heated
2. 2
   Temperaturat reflux overnight
3. 3
   Temperaturcooled
4. 4
   Einengenconcentrated under reduced pressure
5. 5
   workup.ADDITIONThe residue was diluted with water (25 mL)
6. 6
   Extraktionextracted with ethyl acetate (3×50 mL)
7. 7
   TrocknenThe combined organic extracts were dried (Na2SO4)
8. 8
   Filtrationfiltered
9. 9
   Einengenconcentrated
10. 10
    SonstigeThe residue was purified by column chromatography (SiO2, 0-5% methanol in CH2Cl2)

Vorschrift

To a solution of Example 248A (10.0 g, 0.045 mol) in ethanol (100 mL) were added thiourea (3.8 g, 0.05 mol) and triethylamine (6.3 mL, 0.045 mol). The reaction mixture was heated at reflux overnight, then cooled, and concentrated under reduced pressure. The residue was diluted with water (25 mL) and extracted with ethyl acetate (3×50 mL). The combined organic extracts were dried (Na2SO4), filtered and concentrated. The residue was purified by column chromatography (SiO2, 0-5% methanol in CH2Cl2) to afford the title compound. MS (ESI+) m/z 199 (M+H)+.

Quelle