Diethyl Ether → (5-Chlorothiophen-2-YL)(pyridin-2-YL)methanone
Reaction equation
Br[Mg][C:3]1[S:4][C:5]([Cl:8])=[CH:6][CH:7]=1.[C:9]([C:11]1[CH:16]=[CH:15][CH:14]=[CH:13][N:12]=1)#N.CC[O:19]CC>>[Cl:8][C:5]1[S:4][C:3]([C:9]([C:11]2[CH:16]=[CH:15][CH:14]=[CH:13][N:12]=2)=[O:19])=[CH:7][CH:6]=1Participants
4
Procedure
To an etheral solution of bromo(5-chloro-2-thienyl)magnesium (prepared from 2-bromo-5-chloro-thiophene (1.9 g, 9.62 mmol) and magnesium turnings (234 mg, 9.62 mmol) in ether (20 ml)) was dropwise added a solution of 2-cyanopyridine (1 g, 9.62 mmol) in ether (10 ml) at room temperature. After 2 hours, the reaction was quenched by addition of an aqueous saturated solution of NH4Cl. The mixture was extracted with ether. The organic phase was dried over MgSO4 and concentrated under vacuum. The residue was treated with a 2 N HCl solution at 90° C. during 30 minutes. The solution was neutralized by addition of a concentrated solution of NaOH and extracted with ether. The organic phase was dried over MgSO4 and concentrated under vacuum. The residue was purified by chromatography on silica gel (hexane/AcOEt 90/10) to give the (5-chloro-2-thienyl)(2-pyridinyl)methanone 8 as a yellowish oil (1.13 g, 52%).