Reaktion #2270836

Reaktionsgleichung

3-(Benzo[b]thiophen-4-yl)-2-bromo-5,6-dihydroimidazo[2,1-b]thiazole hydrobromide

ethylmagnesium chloride

dimethyl disulphide

→

3-(benzo[b]thiophen-4-yl)-2-(methylthio)-5,6-dihydroimidazo[2,1-b]thiazole hydrochloride

Lösungsmittel

tetrahydrofuran

Reaktionsbedingungen

Aufarbeitung

1. 1
   TemperaturThe mixture was cooled to 0° C.
2. 2
   workup.STIRRINGthe mixture was stirred at ambient temperature for 4 hours
3. 3
   Sonstigequenched by the addition of saturated aqueous ammonium chloride solution (40 ml) and water (50 ml)
4. 4
   ExtraktionThe product was extracted into ethyl acetate (250 ml)
5. 5
   Waschenthe extract was washed with saturated aqueous sodium chloride solution (2×100 ml)
6. 6
   Trocknendried (Na2SO4)
7. 7
   Sonstigethe solvents were removed in vacuo
8. 8
   SonstigeThe residue was purified by flash chromatography over silica using
9. 9
   workup.ADDITIONa 96:4 mixture of ethyl acetate and methanol as eluant
10. 10
    Sonstigethe solvents removed in vacuo
11. 11
    SonstigeThe residue was triturated with 2M ethereal hydrogen chloride solution (20 ml)
12. 12
    Filtrationthe resulting solid was collected by filtration
13. 13
    Waschenwashed with ether (2×20 ml)
14. 14
    Sonstigedried in vacuo

Vorschrift

3-(Benzo[b]thiophen-4-yl)-2-bromo-5,6-dihydroimidazo[2,1-b]thiazole hydrobromide (2.3 g) was added in portions under nitrogen at 0-5° C. over 20 minutes to a stirred solution of ethylmagnesium chloride (2.0 M solution in ether; 6.9 ml) in tetrahydrofuran (35 ml), then the mixture was stirred at 0-5° C. for 20 minutes and at ambient temperature 70 minutes. The mixture was cooled to 0° C. and dimethyl disulphide (0.82 ml) was added, then the mixture was stirred at ambient temperature for 4 hours and quenched by the addition of saturated aqueous ammonium chloride solution (40 ml) and water (50 ml). The product was extracted into ethyl acetate (250 ml), then the extract was washed with saturated aqueous sodium chloride solution (2×100 ml), dried (Na2SO4), and the solvents were removed in vacuo. The residue was purified by flash chromatography over silica using a 96:4 mixture of ethyl acetate and methanol as eluant. Appropriate fractions were combined and the solvents removed in vacuo. The residue was triturated with 2M ethereal hydrogen chloride solution (20 ml) and the resulting solid was collected by filtration, washed with ether (2×20 ml) and dried in vacuo to give 3-(benzo[b]thiophen-4-yl)-2-(methylthio)-5,6-dihydroimidazo[2,1-b]thiazole hydrochloride (0.219 g) as a cream solid, m.p. 95-105° C.

Quelle