Reaktion #2270854

Reaktionsgleichung

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

ethylmagnesium chloride

Dimethyl disulphide

→

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

Lösungsmittel

tetrahydrofuran

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.STIRRINGthe mixture was stirred at this temperature for 10 minutes and at ambient temperature for 4.5 hours
2. 2
   Sonstigeit was quenched by the addition of saturated aqueous ammonium chloride solution (10 ml) and water (20 ml)
3. 3
   ExtraktionThe product was extracted into ethyl acetate (30 ml+2×25 ml)
4. 4
   Waschenthe combined extracts were washed with water (2×25 ml) and saturated aqueous sodium chloride solution (25 ml)
5. 5
   Trocknenthey were dried (MgSO4)
6. 6
   Sonstigethe solvents were removed in vacuo
7. 7
   SonstigeThe residue was purified by flash chromatography over silica using
8. 8
   workup.ADDITIONa 9:1 mixture of ethyl acetate and methanol as eluant
9. 9
   Sonstigethe solvents were removed in vacuo

Vorschrift

3-(Benzo[b]thiophen-5-yl)-2-bromo-5,6-dihydroimidazo[2,1-b]thiazole hydrobromide (0.4 g; prepared as described in Example 28) was added in portions under nitrogen at 0-5° C. over 8 minutes to a stirred solution of ethylmagnesium chloride (2M solution in ether; 1.4 ml) in tetrahydrofuran (10 ml), then the mixture was stirred at 0° C. for 20 minutes and at ambient temperature for 1.25 hours. Dimethyl disulphide (0.14 ml) was added at 0-5° C., the mixture was stirred at this temperature for 10 minutes and at ambient temperature for 4.5 hours, then it was quenched by the addition of saturated aqueous ammonium chloride solution (10 ml) and water (20 ml). The product was extracted into ethyl acetate (30 ml+2×25 ml), the combined extracts were washed with water (2×25 ml) and saturated aqueous sodium chloride solution (25 ml), then they were dried (MgSO4) and the solvents were removed in vacuo. The residue was purified by flash chromatography over silica using a 9:1 mixture of ethyl acetate and methanol as eluant. Appropriate fractions were combined and the solvents were removed in vacuo to give 3-(benzo[b]thiophen-5-yl)-2-(methylthio)-5,6-dihydroimidazo[2,1-b]thiazole (2 mg) as a yellow solid, 1H-nmr (DMSO-d6): δH 2.25 (3H, s, —SCH3), 3.68-4.19 (4H, m, —CH2CH2—), 7.36 (1H, d, J 1.7 Hz, ArH), 7.39-7.41 (1H, m, ArH), 7.54 (1H, d, J 5.45 Hz, ArH), 7.87 (1H, d, J 1.4 Hz, ArH), 7.96 (1H, d, J 8.3 Hz, ArH).

Quelle