Dimethylformamide → 2-(Dimethylamino)-1,3-thiazole-5-carbaldehyde

温度

-78 °C

To a solution of 2-chlorothiazole (300 mg, 2.51 mmol) in distilled tetrahydrofuran (4 mL) at −78° C. was added n-butyllithium (2.5M solution in hexane, 2.58 mmol, 1.03 mL) slowly dropwise. After stirring 10 min at −78° C., N,N-dimethylformamide (2.76 mmol, 0.213 mL) was added and the reaction was warmed slowly to room temperature over 2 h. The reaction mixture was quenched with water (80 μL) and stirred for 24 h at room temperature. After the volatiles were removed under reduced pressure, the residue was diluted with water (25 mL) and extracted with ethyl acetate (2×100 mL). The combined organic layers were washed with brine (25 mL), dried (MgSO4), filtered, concentrated under reduced pressure. The residue was flash chromatographed (silica gel, 50% ethyl acetate in petroleum ether) to yield 2-(dimethylamino)thiazole-5-carboxaldehyde (170 mg, 43% yield) as an orange solid.