Reaktion #2270776

Reaktionsgleichung

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

ethylmagnesium chloride

Dimethylformamide

→

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

Lösungsmittel

tetrahydrofuran

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.STIRRINGthe mixture was stirred at ambient temperature for 3 hours
2. 2
   Temperaturcooled to 15° C.
3. 3
   Sonstigequenched by the cautious addition of saturated aqueous ammonium chloride solution (10 ml) and water (10 ml)
4. 4
   workup.ADDITIONEthyl acetate (20 ml) was added
5. 5
   workup.STIRRINGthe mixture was stirred at ambient temperature for 18 hours
6. 6
   ExtraktionThe product was extracted into ethyl acetate (2×50 ml)
7. 7
   Waschenthe combined extracts were washed with saturated aqueous sodium chloride solution (50 ml)
8. 8
   Trocknendried (MgSO4)
9. 9
   Sonstigethe solvents were removed in vacuo
10. 10
    SonstigeThe residue was triturated with propan-2-ol (5 ml)
11. 11
    Filtrationthe resulting solid was collected by filtration
12. 12
    Waschenwashed with propan-2-ol (5 ml)
13. 13
    Sonstigedried in vacuo at 60° C.

Vorschrift

3-(Benzo[b]thiophen-4-yl)-2-bromo-5,6-dihydroimidazo[2,1-b]thiazole hydrobromide (1.2 g) was added in portions under nitrogen at 5-10° C. over 5 minutes to a stirred solution of ethylmagnesium chloride (2.0 M solution in ether; 4.5 ml) in tetrahydrofuran (20 ml), then the mixture was stirred at 5-15° C. for 2 hours. Dimethylformamide (1.3 ml) was added at 5-10° C. over 5 minutes, then the mixture was stirred at ambient temperature for 3 hours, cooled to 15° C. and quenched by the cautious addition of saturated aqueous ammonium chloride solution (10 ml) and water (10 ml). Ethyl acetate (20 ml) was added and the mixture was stirred at ambient temperature for 18 hours. The product was extracted into ethyl acetate (2×50 ml) and the combined extracts were washed with saturated aqueous sodium chloride solution (50 ml), dried (MgSO4), and the solvents were removed in vacuo. The residue was triturated with propan-2-ol (5 ml) and the resulting solid was collected by filtration, washed with propan-2-ol (5 ml) and dried in vacuo at 60° C. to give 3-(benzo[b]thiophen-4-yl)-5,6-dihydroimidazo[2,1-b]thiazole-2-carboxaldehyde (0.37 g) as a brown solid which was used without further purification.

Quelle