2-Chloro-3-oxopropanenitrile

107-31-3

107-14-2

53106-70-0

In a dry round-bottomed flask under argon protection, sodium methanolate (7.14 g, 0.13 mol) was suspended in anhydrous tetrahydrofuran (90 mL) and the suspension was cooled to -5 °C. Methyl formate (9 mL, 0.15 mol) was slowly added dropwise over 1 min using a syringe, and stirring was continued for 20 min keeping the temperature at -5 °C. Subsequently, chloroacetonitrile (8.33 mL, 0.13 mol) was added dropwise over 45 min through a dropping funnel. The color of the reaction mixture gradually changed from white to yellow and finally orange after stirring for 2 h at -5 °C. The cooling bath was removed and the reaction mixture was allowed to warm up naturally to room temperature. A small amount of the reaction mixture was treated with concentrated hydrochloric acid and analyzed by thin layer chromatography (TLC) using 100% ethyl acetate as eluent, which showed the presence of the target product (Rf = 0.45). The reaction mixture was cooled to 0 °C and concentrated hydrochloric acid (12 mL) was added slowly and dropwise, at which point the color of the mixture changed to cherry red. The resulting suspension was filtered through a diatomaceous earth pad and the diatomaceous earth was washed with ethyl acetate until the filtrate was colorless. The collected filtrate was concentrated under reduced pressure in a water bath at not more than 40 °C to give 2-chloro-2-formylacetonitrile in quantitative yield as a black oil, which was used directly in the next reaction without further purification. The NMR hydrogen spectrum (400 MHz, CDCl3) showed δ 9.38 (s, 1H); the NMR carbon spectrum (400 MHz, DMSO-d6) showed δ 168.2, 126.6, 67.8. Reference: Brooks et al. 2012.