Condensed Isoquinolines. 16. Enamine Properties of Benzo[4,5]imidazo[1,2-b]isoquinolin-11(5H)-one in Terms of Its Acylation Reactions

Condensed isoquinolines. 20. Characteristic features of thermal rearrangement of 7,12-dihydro-5H-isoquino[2,3-a]quinazolin-5-one to form 6,11-dihydro-13H-isoquino[3,2-b]quinazolin-13-one

“…The basis for this hypothesis was also the previously described example [7] of oxidative dimerization of benzimidazo[1,2-b]isoquinolin-11(5H)-one, leading to a dimer with a symmetric structure. The half set of signals in the NMR spectra of structure 3 is due to the high symmetry of its molecule.…”

Condensed isoquinolines 24. Reaction of 6,11-dihydro-13H-isoquino[3,2-b]quinazolin-13-one with carbonyl compounds

“…We and other authors have previously reported the acylation of compound 4 [8] and benzimidazo[1,2-b]isoquinolin-11(5H)-one (5) [10]. It was found that compound 4 exists in DMSO in the tautomeric imine and enamine forms but compound 5 only in the enamine form.…”

“…In the case of p-chlorobenzoyl chloride the monoacyl derivative 6 is obtained in 65% yield and from chlorides of acetic, benzoic, and p-toluic acids the diacyl derivatives 7a-c in 65-70% yields, as shown from the results of their elemental analysis and from their 1 H NMR spectroscopic data. In the examples of the acyl-substituted compounds 4 and 5 we have previously [8,10] determined criteria for assigning the structures of the acylation products through the presence in the 1 H NMR and IR spectra of characteristic signals for =CH, CH 2 , and NH groups and through the trend in the shifts of the benzene ring aromatic protons annelated to the heterocyclic system. For the 6-(4-chlorobenzoyl)-5,11-dihydro-13H-isoquino-[3,2-b]quinazolin-13-one (6) its spectroscopic characteristics agreed fully with those of the C-acyl-substituted compounds of 4 and 5.…”

“…When examining the acylation of the benzimidazo[1,2-b]isoquinolinone 5 by acid anhydrides and chlorides in the presence of base (NaOAc and pyridine) [10] it was found that the reaction with the anhydrides gives exclusively the C-acylated compounds and in the presence of base a mixture of the C-and N-acylated products. Further, the fraction of the latter in the mixture indicated became greater with increase in the basicity of the reaction medium.…”

“…Heating compound 1a with chloroacetyl chloride in the presence of NaHCO 3 gave us a member of the novel heterocyclic system 7H,8H-2a,7a-diazacyclopenta[f,g]napthacene-1,7(2H)-dione (10) which is the product of simultaneous acylation and intramolecular N-alkylation.…”