反应详情

Pyrrole (150 mmol) and trifluoroacetaldehyde methyl hemiacetal (75 mmol) in tetrahydrofuran are heated at reflux with catalytic amounts of hydrochloric acid for 2 hours under an inert atmosphere. GC analysis of the reaction mixture indicated the presence of the desired dipyrromethane in greater than 80% yield. Neutralization of the acid followed by work up and chromatography gave the pure bis(pyrrol-2-yl)-trifluoromethylmethane 3 (R3 =CF3)). MS:m/z=214. This preparation has been disclosed in Wijesekera U.S. patent application Ser. No. 08/143,261 filed on Oct. 26, 1993.