Kysil A. Cycloaddition and acylation by carboxylic acids chloroanhydrides of pyrimido[2,1-a]isoindolone, triazolo[5,1-а]isoindole and imidazo[2,1-a]isoindole derivatives

Isoindol-isoindoline isomerism is described for condensed isoindoles; each isomer is obtained in the individual state. It is shown that compounds which have an isoindole structure react with aldehydes and derivatives of maleimide. It is established that substituted in the quinazoline fragment of 6-alkyl-5,6-dihydroisoindolo[2,1-a] quinazoline-5-ones react with derivatives of maleimide to form Diels-Alder endo-adducts regardless of initial compounds ratio (1:1 or 1:2) (unlike the unsubstituted system). It is shown that methylthieno[3',2':5,6]pirimido[2,1-a] isoindol-4(5H)-one react with derivatives of maleimide at a ratio of initial compounds 1:1 and 1:2 to form Diels-Alder adducts 1:1. It is established that benzofuro[2',3':5,6] pyrimido[2,1-a]isoindol-6(5H)-ones react with derivatives of maleimide at the ratio of initial compounds 1:1 to form the mixtures of Diels-Alder and Michael-Diels-Alder adducts. It is shown that benzofuro[2',3':5,6] pirimido[2,1-a]isoindol-6(5H)-ones react with the derivativesof maleimide at a ratio of initial compounds 1:2 at heating in methanol to form Michael-Diels-Alder adducts; performing of this reaction in boiling DMF results in the skeletal rearrengement of tricyclic intermediate 7-azabenzonorbornene 1:2. It is shown that derivatives of imidazo[2,1-a]isoidoles react with derivatives of maleimide at a ratio of initial compounds 1:2 at heating in a toluene to form rearranged adducts of Michael-Diels-Alder 1:2. It is found that novel meso-substituted monomethynecyanines are formed by acylation of triazolo[5,1-a]isoindoles and imidazo[2,1-a]isoidoles with acyl chlorides.