Bicyclic 6-6 Systems with One Ring Junction Nitrogen Atom: No Extra Heteroatom

ChemInform Abstract: Reactions of Alkyl (Z)‐2‐[(E)‐2‐Ethoxycarbonyl‐2‐(2‐pyridinyl)ethenyl] amino‐3‐dimethylaminopropenoates with C‐ and N‐Nucleophiles. The Synthesis of Fused Pyranones, Pyridinones and Pyrimidinones.

“…The 1 H nmr spectra were obtained on a Bruker Avance DPX 300 (300 MHz) spectrometer in such solvent as dimethyl sulfoxide-d 6 and deuteriochloroform with tetramethylsilane as internal standard, MS spectra on an AutoSpecQ spectrometer, IR spectra on a Perkin-Elmer 1310 infrared spectrophotometer and elemental analyses for C, H, and N on a Perkin-Elmer CHN Analyser 2400. Experimental and analytical data are given in Tables 1 and 2. Ethyl 3-Dimethylamino-2-(2-pyridinyl)propenoate (2) was Prepared According to the Procedure Described in the Literature [16]. (26) were prepared according to the procedures described in the literature [11].…”

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Alkyl 2-[2-ethoxycarbonyl-2-(2-pyridinyl)ethenyl]amino-3-dimethylaminopropenoates 3 and 4 were transformed with C-and N-nucleophiles into β-heteroaryl-α,β-didehydro-α-amino acid derivatives 13-16, substituted 3-amino-4H-quinolizin-4-one 17, 2H,5H-benzo[b]pyran-2,5-dione 18 and 19, 2H,5Hpyrano[4,pyran-2,5-dione 20, 2H,5H-pyrano[3,2-c]benzo[b]pyran-2,5-dione 21, 2H-1-benzopyran-2one 22 and 24, pyrido[1,2-a]pyrimidin-4-one 31-34 and 39 derivatives, and N-heteroaryl-1H-imidazole-4carboxylates 37 and 38. J. Heterocyclic Chem., 38, 869 (2001).Quinolizines, pyridopyrimidines, benzopyrans, pyranopyrans and related fused systems are the basic structures of many naturally occurring alkaloids and their synthetic derivatives exhibiting various biological activity [1][2][3][4][5].Recently, alkyl 2-substituted 3-(dimethylamino)propenoates and their cyclic analogs have been shown to be versatile and efficient reagents for the preparation of various heterocyclic systems [6], including some natural products, such as aplysinopsins and analogs [7]. This methodology has opened also an easy access to substituted 4H-quinolizin-4-ones, pyridopyrimidines and other heterocyclic systems with an amino group in 3 position of the newly formed heterocyclic system [8][9][10].

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“…Quinolizines, pyridopyrimidines, benzopyrans, pyranopyrans and related fused systems are the basic structures of many naturally occurring alkaloids and their synthetic derivatives exhibiting various biological activity [1][2][3][4][5].…”

Parallel Synthesis of 3-Amino-4H-Quinolizin-4-ones, Fused 3-Amino-4H-Pyrimidin-4-ones, and Fused 3-Amino-2H-Pyran-2-ones

“…Spectral data for novel hydrobromide and hydrochloride salts of amines 7a-v were in agreement with spectral data for closely related heterocyclic compounds. [9][10][11]37,41 Amines 7a-j (method A), amine 7j,k,m,n-q,s hydrobromides (method B), and amine 7j,l,n,o hydrochlorides (method C) were not prepared in analytically pure form. Their structures were confirmed by HRMS and because (a) they afforded the desired heterocyclic amines in high purity and in moderate to high yields and (b) the products precipitated from the cooled reaction mixtures and were simply isolated by filtration.…”

“…[23][24][25][26][27][28][29][30] Just recently, various coumarin scaffold-containing compounds were reported as antitumor agents, 31 selective aromataze inhibitors, 32 and nitric oxide production inhibitors. 33 Probably the most straightforward synthesis of quinolizinones, 9 fused 4H-pyrimidin-4-ones, 10 and fused 2H-pyran-2-ones 11 is cyclocondensation reaction between a (hetero)cyclic 1,3-dinucleophile with an appropriate 1,3-dielectrophile, for example, with a 1,3-dicarbonyl compound or its analogue. 2-Substituted alkyl 3-(dimethylamino)prop-2-enoates and related enaminones are a group of easily available enamino masked alkyl R-formyl acetates, which are versatile reagents in heterocyclic synthesis.…”