Reaktion #2270856

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

Lösungsmittel

tetrahydrofuran

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigeprepared in a manner similar to
2. 2
   TemperaturThe mixture was cooled to 0° C.
3. 3
   workup.STIRRINGthe mixture was stirred at ambient temperature for 18 hours
4. 4
   Sonstigequenched by the addition of saturated aqueous ammonium chloride solution (150 ml)
5. 5
   SonstigeThe majority of the tetrahydrofuran was removed in vacuo
6. 6
   workup.ADDITIONthe residue was diluted with water (200 ml)
7. 7
   Extraktionthe product was extracted into ethyl acetate (400 ml)
8. 8
   WaschenThe extract was washed with water (300 ml) and saturated aqueous sodium chloride solution (2×150 ml)
9. 9
   Trocknenit was dried (Na2SO4)
10. 10
    Sonstigethe solvents were removed in vacuo
11. 11
    SonstigeThe residue was purified by Biotage flash chromatography over silica using
12. 12
    workup.ADDITIONa 96:4 mixture of ethyl acetate and methanol as eluant
13. 13
    Sonstigethe solvents removed in vacuo

Vorschrift

3-(Benzo[b]thiophen-4-yl)-2-bromo-5,6-dihydroimidazo[2,1-b]thiazole hydrobromide (15 g; prepared in a manner similar to that described in Example 22) was added in portions under nitrogen at 0-5° C. over 20 minutes to a stirred solution of ethylmagnesium chloride (2M solution in ether; 45 ml) in tetrahydrofuran (225 ml), then the mixture was stirred at 0-5° C. for 2 hours. The mixture was cooled to 0° C. and dimethyl disulphide (5.4 ml) was added, then the mixture was stirred at ambient temperature for 18 hours and quenched by the addition of saturated aqueous ammonium chloride solution (150 ml). The majority of the tetrahydrofuran was removed in vacuo, the residue was diluted with water (200 ml) and the product was extracted into ethyl acetate (400 ml). The extract was washed with water (300 ml) and saturated aqueous sodium chloride solution (2×150 ml), then it was dried (Na2SO4), and the solvents were removed in vacuo. The residue was purified by Biotage 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 to leave 3-(benzo[b]thiophen-4-yl)-2-(methylthio)-5,6-dihydroimidazo[2,1-b]thiazole (7.3 g) as a pale yellow solid, m.p. 104-107° C.

Quelle