Shkilna N. Investigation of enamine properties of 5,11-dihydrobenzimidazo[1,2-b]isoquinolin-11-one and 3,9-dihydropyrrolo[2,1-b]quinazolin-1(2H)-one in alkylation and acylation reactions

The acylation of benzimidazo[1,2-b]isoquinolin-11(5Н)-one at N-5 and C-6 positions as a function of the nature of the acylating agent was studied. C-acylation is a dominating direction of the reactions. The interaction with chloroanhydrides of a-halosubstituted carbon acids yields the products of acylation which are converted into derivatives of new heterocyclic system such as 7Н-2а,6b-diazobezo[b]cyclopenta[l,m]phluoren-1,7(2Н)-dione in presence of bases. The alkylation of benzimidazo[1,2-b]isoquinolin-11(5Н)-one proceeds at N-5 or C-6 atoms which depends on the type of alkylation reagent and the reaction conditions. C(6)-alkylation occurs in the case of phenacyl and benzyl halogenides. The same position is mostly targeted in case of double alkylation. The reaction with о-xylilenedibromide leads to spiro[benzimidazo[1,2-b]isoquinolin-6,2'-indan]-11-one and 1,6-dihydro-11Н-6а,11b-diazabenzo-[b]benzo[5,6]cyclohepta[1,2,3-lm]fluoren-11-one - the derivatives of new heterocyclic systems. We have found thatthe reaction between benzimidazo[1,2-b]isoquinolin-11(5Н)-one and о-bromomethylphenylacetonitril proceeds in an unexpected manner. It is followed by rearrangement of the intermediate which leads to 12,12а-dihydrobenzo[b]phenantridine-5(6Н)-one. The interaction between benzimidazo[1,2-b]isoquinolin-11(5Н)-one and activated olefins yields the derivatives of 3,10-dioxo-3Н,10Н-benzimidazo[1,2,3-іj]benzo[c][1,8]naphtiridine as a result of Michael's reaction and consequent intermolecular cyclization at N-5 position, The alkylation as well as the acylation of 3,9-dihydropyrrolo[2,1-b]quinazolin-1(2H)-one at N-4 position give tertiary salts which are not stable to hydrolysis. Aryl derivatives such as 3-[(E)-arylmethyliden]-3,9-dihydropyrrolo[2,1-b]quinazolin-1(2H)-ones were synthesized by condensation of quinazolin-2-propionic acid and aromatic aldehydes. The reduction of these compounds with sodium borohydride leads to 3-[(E)-arylmethyliden]-1,2,3,9-tetrahydropyrrolo [2,1-b]-quinazolin-1-ols.