Piperazine → Caldaret

Participants

Reaction Steps

According to the method described in Example 1 of the Japanese Patent Unexamined Publication (KOKAI) No.(Hei)3-7263/1991, 2-fluoro-5-methylbenzenesulfonic acid (0.76 g) and piperazine (3.44 g) were reacted in a sealed tube in the presence of cuprous iodide (0.76 g) and copper powder (0.26 g) at 160° C. for 8 hours, and then the reaction product was purified by silica gel chromatography (eluent: chloroform: methanol: acetic acid=100:100:3) to give anhydrous crystals of 2-(1-piperazinyl)-5-methylbenzenesulfonic acid (0.67 g, yield: 65.0%).

Provenance & Evidence