The reaction of bisbenzimidazolium salt with Grignard reagents and a new sy
nthetic method of alpha -diketones from bisbenzimidazolium salt and Grignar
d reagents are reported. The structures of all alpha -diketones are charact
erized by elemental analyses, infrared spectroscopy and H-1 MM spectroscopy
. The influences of the various Grignard reagents on the yield of alpha -di
ketones and the mechanism are discussed, and a new convenient synthetic met
hod for alpha -diketones is provided.