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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

“…In the 1 H NMR spectrum of the mixture, signals from eight aromatic and three aliphatic protons corresponded to the unknown product: 6.51 ppm (s), 5.87 ppm (d), and 4.68 ppm (d) with 2 J = 16.8 Hz (Table 1). Previously in 6-benzylisoquino[3,2-b]quinazoline, we observed a similar set of signals and a similar type of splitting of the signals from protons of the methylene group C (11) H 2 [5]. This allowed us to assume that during rearrangement of compound 2 to form quinazolinone 1, substitution at one of the methylene groups occurs in structure 1, leading to the appearance of a chiral center and consequently to the appearance of diastereotopicity.…”

“…In this case, the protons of the methylene groups bonded to the nitrogen atom proved to be nonequivalent, and are observed as two multiplets with chemical shift difference ∆δ = 0.11 ppm (Table 1), which suggests conformational anchoring of the position of the morpholine ring. The protons of the methylene group C (11) H 2 , as would be expected [5], are also magnetically nonequivalent and give two doublets with ∆δ = 0.71 ppm and 2 J = 15.5 Hz.…”

“…The biological activity has been studied only in the case of 6,11-dihydro-13H-isoquino [3,2-b]quinazolin-13-one (1), for which a rather high level of antifungal and antimicrobial activity has been observed [3]. Earlier [4,5], a relatively simple method was developed to obtain quinazolinone 1 and its 6-alkyl derivatives, including rearrangement of the corresponding isomeric derivatives with an angular structure: 7,12-dihydro-5H-isoquino[2,3-a]quinazolin-5-ones (2). In this paper, we consider some features of this process and also the reaction of oxidation of compound 1.…”

Condensed isoquinolines 25. Alkylation of 6,11-dihydro-13H-isoquino[3,2-b]quinazolin-13-one

“…3,9-dioxo-3H,9H,11H-benzo [5,6] We have previously studied alkylation, one of the characteristic reactions of enamines, using benzimidazo[1,2-b]isoquinolin-11(5H)-one [2,3] and 7,12-dihydro-5H-isoquino[2,3-a]quinazolin-5-one [4,5] as examples. It seemed of interest to investigate the characteristics of this reaction for the linear isomer -6,11-dihydro-13H-isoquino [3,2-b]quinaxolin-13-one (1) which had been shown previously [1] to be ambident as nucleophilic agent with the example of reactions with carbonyls.…”

Condensed isoquinolines 22. Synthesis and properties of 6,11-dihydro-13H-isoquino-[3,2-b]quinazolin-13-ones

“…Antifungal activity of the latter has been observed [3]. A relatively simple method for the synthesis of derivatives of isoquino[3,2-b]quinazolin-13-one 1 consists of the thermal rearrangement of the isomeric derivatives of 7,12-dihydro-5H-isoquino-[2,3-a]quinazolin-5-one (2) [4,5]. We have previously studied [1] the reaction of o-bromomethylphenylacetonitrile (o-BMPA) with anthranilic acids and their esters, by which a series of Ar-substituted isoquino[2,3-a]quinazolines were obtained.…”