Piperazine → Caldaret

Participants

Reaction Steps

According to the method described in Example 1 of Japanese Patent Application Laid-Open No. 3-7263, 2-fluoro-5-methylbenzene sulfonic acid (0.76 g) was reacted with piperazine (3.44 g) in the co-presence of cuprous iodide (0.76 g) and copper powder (0.26 g) in a sealed tube at 160° C. for 8 hours. Then, the reaction product was purified on silica gel column chromatography (eluent=chloroform: methanol: acetic acid=100: 100: 3) to give anhydrous crystal of 2-(1-piperazinyl)-5-methylbenzenesulfonic acid derivative (0.67 g, yield=65.0%).

Provenance & Evidence