Diethyl Malonate → Diethyl 2-(benzo[d]thiazol-2-yl)malonate

Participants

Reaction Steps

Into a solution of 1,3-diethyl propanedioate (280 g, 1.75 mol, 3.00 equiv) in tetrahydrofuran (1000 mL) in a 2000-mL round-bottom flask purged and maintained with an inert atmosphere of nitrogen was added sodium hydride (46.15 g, 1.92 mol, 2.00 equiv) in portions. After stirring for 30 min at room temperature, 2-chloro-1,3-benzothiazole (100.0 g, 589.51 mmol, 1.00 equiv) was added. The reaction mixture was stirred for 20 h at 70° C. in an oil bath, cooled to room temperature, quenched with sat. ammonium chloride (200 mL) and extracted with ethyl acetate (3×500 mL). The combined organic layers were dried over anhydrous sodium sulfate. After filtration and concentration under vacuum, the residue was triturated with 1×500 mL of dichloromethane. The solid was collected by filtration to give 166 g of 1,3-diethyl 2-(1,3-benzothiazol-2-yl)propanedioate as a white solid. MS m/z [M+H]+ (ESI): 294.

Provenance & Evidence