US EPA

5178497 

Journal Article 

The reaction of arylcoppermagnesium and other organometallic reagents with phthalic anhydride 

Rahman, MT; Nahar, SK 

1992 

Yes 

Journal of Organometallic Chemistry
ISSN: 0022-328X
EISSN: 1872-8561 

ELSEVIER SCIENCE SA LAUSANNE 

LAUSANNE 1 

425 

1-2 

201-208 

English 

10.1016/0022-328X(92)80036-W 

WOS:A1992HJ16400020 

http://www.sciencedirect.com/science/article/pii/0022328X9280036W
Exit
 

Arylcoppermagnesium reagents, prepared from 5ArMgX + 2.5CuI, (Ar = 4-CH3C6H4, 4-CH3OC6H4, 4-ClC6H4, 2-C4H3S react with one equivalent of phthalic anhydride in ether or THF at −5'C for 2.5 h to give 2-aroylbenzoic acids in 83–98% yields. The phenylcopperma reagent (Ar  C6H5 under similar conditions gives 2-benzoylbenzoic acid and 3,3-diphenylphthalide in 40–42% and 42–45% yield, respec The yield of the 2-benzoylbenzoic acid rises to 93% in the presence of dimethyl sulphide. Under these conditions no phthalide is formed. Lithium diphen reacts with phthalic anhydride in ether-hexane to give 92% of 2-benzoylbenzoic acid and 7% of 3,3-diphenylphthalide. The reaction of phenylcopper reage from PhMgBr + CuI, under similar conditions is slow and gives 2-benzoylbenzoic acid in 15% yield. The reaction of phenylmagnesium bromide in the presen of catalytic amounts of copper(I) iodide gives unsatisfactory results. Use of two equivalents of phenyllithium with one equivalent of phthalic anhydrid hand, affords 3,3-diphenylphthalide in 77% yield. The mechanisms of these reactions are discussed.