The Reaction of Arylmagnesium Halides with Succinic Anhydride

Department of Chemistry, University of Dhaka, Dhaka 1000, Bangladesh
Manuscript received 8 December 1993

The reaction of equimolar amounts of phenylmagnesium bromide and succinic anhydride in THF at -78° for 2 h gives subsequent to hydrolytic work-up, 3-benzoylpropionic acid in 76% yield and 4,4-diphenyl-4-butyro- lactone in 3% yield. When two molar equivalents of the Grignard reagent are employed, the yields of these products are respectively 85 and 14%. On the other hand, when four equivalents of the Grignard reagent are employed for every equivalent of succinic anhydride at 66°, a diketone, 1,4-diphenylbutane-1,4-dione is obtained in 72% yield. Other products include 4,4-diphenyl-4-butyrolactone (19%) and 3-benzoylpropionic acid (6%). Under comparable conditions, 4-methyl- and 4-methoxyphenylmagnesium halides react similarly with succinic anhydride, giving fair yields (49-53%) of the corresponding diketones. However, 4-chlorophenylmagnesium chloride only gives the keto-acid (12%) and lactone (42%), but no diketone.