The general procedure for the synthesis of ethyl 1-cyanocyclopropanecarboxylate from 1,2-dibromoethane and ethyl cyanoacetate was as follows: a suspension of ethyl cyanoacetate (11.3 g, 0.1 mol), 1,2-dibromoethane, tetrabutylammonium bromide (Na 4 (n-Bu)4Br) and potassium carbonate (K 2 CO 3 ) in N,N-dimethylformamide (DMF, 100 mL) was heated to 80 °C and reacted overnight. Upon completion of the reaction, the mixture was poured into water (600 mL) and extracted with ethyl acetate (EtOAc, 3 x 50 mL). The organic layers were combined, washed with saturated saline, dried over anhydrous sodium sulfate (Na 2 SO 4 ) and concentrated under reduced pressure to give the crude product. The crude product was purified by silica gel column chromatography (eluent: petroleum ether/ethyl acetate = 10:1) to afford ethyl 1-cyanocyclopropanecarboxylate (10 g, yield: 72%).1H NMR (CDCl3, 400 MHz): δ 4.21 (q, J = 7.2 Hz, 2H), 1.65-1.61 (m, 2H), 1.58-1.55 (m, 2H) , 1.28 (t, J = 7.2 Hz, 3H).
