Chlorosuccinimide → Methyl 5-chloro-4-(4-chloro-1-ethyl-1H-pyrazol-5-yl)-2-thiophenecarboxylate

Participants

Reaction Steps

Methyl 5-chloro-4-(1-ethyl-1H-pyrazol-5-yl)-2-thiophenecarboxylate (1.8 g, 6.65 mmol) and NCS (1.3 g, 9.74 mmol) in THF (10 mL) were heated to 70° C. under N2 for 2 h. The reaction solution was concentrated and purified on silica (EtOAc/Hex, 10-30%) to afford the title compound (1.5 g, 74%) as a syrup: LC-MS (ES) m/z 305 (M+H)+.

Provenance & Evidence