A New Synthesis of Maleic Anhydrides

Russian Chemical Bulletin, International Edition, Vol. 56, No. 3, pp. 509—512, March, 2007

509

High pressure assisted addition of (methoxyphenyl)maleic anhydrides to dienes. Synthesis of 3a aryltetrahydroisoindole 1,3 diones

A. I. Roshchin, Yu. V. Kuznetsov, and E. V. Polunin N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 47 Leninsky prosp., 119991 Moscow, Russian Federation. Fax: +7 (495) 135 5328. E mail: polunin 507@yandex.ru

A new synthesis of (2 and 4 methoxyphenyl)maleic anhydrides was accomplished, the reactions of which with cyclopentadiene and 3 sulfolene, serving as a 1,3 butadiene equiva lent, furnished the [4+2] cycloadducts. The latter were converted into imides of 2 aryl bicyclo[2.2.1]hept 5 ene 2,3 dicarboxylic and 1 arylcyclohex 4 ene 1,2 dicarboxylic acids respectively. Key words: Diels—Alder reaction, Heck reaction, fumaric acid, maleic anhydrides, tetrahydro 2 benzofuran 1,3 diones, tetrahydroisoindole 1,3 diones, sulfolene, cyclopenta diene, high pressure, imides.

By now, only a limited number of 3a aryl derivatives of tetrahydroisoindole 1,3 dione 1, 2 (see Refs 1, 2) and hexahydroisoindole 3 (see Ref. 3) was described in the chemical literature. Compound 1 was found to have a soporific effect,1 compounds of type 3, an analgesic or analgesic antagonists activity,3 and compound 2 was pre dicted by PASS4 program to have the immunomodulating activity with 0.94 probability.

3а Aryltetrahydroisoindole 1,3 diones as imides of cyclohex 4 ene 1,2 dicarboxylic acid can be synthesized from the corresponding anhydrides. The latter can be obtained, for example, by [4+2] cycloaddition of dienes and arylmaleic anhydrides. However, synthesis of aryl maleic anhydrides often turns out to be labourous (the representative example is described in Ref. 5: four stages and 39% yield) and their activity as dienophiles in Diels—Alder reaction is relatively low. In the present work, a convenient method for the syn thesis of...