40594-98-7

4648-54-8

623-47-2

40594-98-7

Ethyl propargylate and trimethylmethylsilyl azide were injected through a 2 mL loop in a Vapourtec R2+/R4 flow system equipped with three PTFE reactor coils (10 mL) and a 250 psi back pressure regulator. The flow rate was set at 0.5 mL/min and the residence time was 1.5 hours. The system was heated to 140°C. Injections were performed every 40 min and the solvent used was acetonitrile. The total mixture flowing from the reactor was collected and a total of 5 injections were performed. The collected mixtures were combined and the acetonitrile was removed under vacuum by rotary evaporator (the collection flask of the rotary evaporator was pre-filled with saturated aqueous NaHCO3 solution to quench any HN3 that might be generated). The residual solid was dissolved in ethyl acetate and the organic phase was washed with saturated brine (3 times), dried over anhydrous sodium sulfate, filtered and the solvent evaporated. The crude product was stirred with a minimal amount of ether, filtered and dried to give ethyl 1H-1,2,3-triazole-5-carboxylate (8.65 g, 81% yield) as a white solid. Mass spectrum (ESI): m/z=142.1 [M+H]+.