No abstract

No abstract

The preparation of substituted N‐arylisoindolines 3 from simple furan derivatives 1 is reported. Oxatricycloadducts 2, readily accessible by intramolecular Diels‐Alder reaction are susceptible to acidic reagents yielding aromatized products 3 by a ring‐opening reaction via intermediate carbocation.

N‐Alkenyl‐N‐(5‐substituted‐2‐furfuryl)‐N‐p‐toluidines 1–10 have been selected to study the intramolecular Diels‐Alder reaction of furans. New epoxyisoindolines 11–20 were prepared and fully characterised.

The new tertiary furfurylamine with triple bond as a dienophylic part i.e. N-(5-methyl-2-furfuryl)-N-prop-2-ynyl-p-toluidine (1) was prepared and the intramolecular Diels-Alder reaction of the amine (1) was performed under microwave irradiation conditions and by heating a benzene solution of the amine under nitrogen. Comparing the results of the usual thermal and the MAOS reaction, we confirmed our expectations that MAOS could promote the outcome of IMDA reaction of the suitably N-substituted tertiary 2-furfuryl-amines. In the present example, N-p-tolyl-5-methyl-5,7a-dihydro-5,7a-epoxyisoindoline was obtained in much better yield and of higher purity.