Imidazo quinoxalin-4-ones

According to the third criterion, quinoxaline is the base component The heterocycle imidazole, which is fused to the base component, is numbered in the usual way the pyridine ring, however, is denoted by 1, 2, and so on, and it is not necessary to mark the double bonds. Pyrido[T,2 l,2]imidazo denotes one ring fusion, imidazo[4,5-b]quinoxaline the... 

Scheme 4.48 Three-component condensation of Af-Boc-o-diaminobenzenes, ethyl glyoxylate and substituted tosyl isocyanates for the synthesis imidazo[l,5-a]quinoxalin -ones...

The presence of the pyrrolidine, morpholine, cyclohexane, piperidine, or aza-cycloheptane moiety in the 1-position of imidazo[l,5-a]quinoxalin -ones, along with amide groups in the 7(8)-position, leads to inhibition of phosphodiesterase 9 (PDE9) therefore, such compounds are used for developing dmgs that eliminate urination disorders (Okada et al. 2009 Kaizawa et al. 2011). 

Imidazo[2, r 2,3]thiazolo[4,5-f>]quinoxalines were obtained in one step from imidazole precursors <02IJH257>. Intramolecular quatemization reactions of either 158 or 159 ultimately afforded quinoxalines 161 from substituted acetanilides 160 <02JCS(P1)790>, and a two-step... 

Some very clever syntheses of pyrazines were reported. Tandem Mn02-mediated oxidation followed by in situ trapping with aromatic or aliphatic 1,2-diamines was shown to give rise to quinoxalines, dihydropyrazines, pyrazines, and piperazines without the need to isolate highly reactive 1,2-dicarbonyl intermediates <03CC2286>. A new intramolecular cyclization route to highly substituted chiral 6,7-dihydro-5//-imidazo[l,5-a]pyrazin-8-ones like 157 from Meldrum s acid was developed <030L3907>, and 5-chloropyrido[3,4-6]pyrazines were prepared from 1,2-dicarbonyl compounds and 2-chloro-3,4-diaminopyridine <03H(60)925>. A synthesis of... 

Imidazol 1,2-0Ipyridine, 879, 13.39 Imidazol I..5-a pyridine, 874. 13.39 Imidazol 1,5-a Ipyridine, 1.321 lmidazo 4,5-6jpyridine, 741 Imidazol 1,2-a ipyridin-3-one. 1000 Imidazol 1,2-a pyridin-5-one. 917 Imidazol 1,2-ajpyridin-7-one. 918 Imidazo 4,5-6 pyridin-2-one. 1129 Imidazo 4.5-b)pyridin-2-one, 948 Imidazo 4,5-( pyridin-2-one, 1139 Imidazol 1,2-a]pyrimidine, 874 Imidazoll,2-( pyrimidine, 998, 1237 Imidazol 1,2-a pyrimidin-4-one, 1009 Imidazol 1,2-a pyrimidin-5-one, 1300 Imidazoj 1,2-a jpyrimidin-7-one, 1300 Imidazol 1.2-ajpyridin-7-one. 1106 Imidazoll,2-r quinazolin-5-one, 886 lmidazo 4,5-/ quina/olin-7-one, 684 lmidazo 4.5-/> quinazoiin-8-one, 1161 Imidazol 1,5-a Iquinoiine, 998 Imidazoj4.5-( quinoline, 1313 Imidazo 4..5-/Iquinoiine, 981. 989 Imidazo 4,5-/ quinolin-7-one. 684 Imidazol 1,2-a Iquinoxaline, 975 Imidazol 1.5.4-de quinoxaline, 776 Imidazol I 3,4-de quinoxaline-2.5-dione, 1000... 

Although the 1,3-diphenyl 2-oxo compound 63 is stable to acid hydrolysis, imidazo[4,5-h]quinoxaline itself undergoes very ready hydrolytic ring opening. Hot dilute hydrochloric acid gives 3-aminoquinoxalin-2-one (74), and hot alkali affords 2,3-diaminoquinoxaline (57). Similarly acid treatment of the 2-methyl N-oxides 72 and 73 provides the quinox-aline N-oxides 75 and 76, respectively. ... 

LaBarbera DV, Skibo EB (2005) Synthesis of imidazo[l,5,4-de]quinoxalin-9-ones, benzimidazole analogues of pyrroloiminoquinone marine natural products. Bioorg Med Chem 13 387-395... 

A number of preparations of different types of imidazoquinoxalines were reported in 2013. Ma and coworkers devised an efficient one-pot synthesis of benzo[4,5]imidazo[l,2-a]quinoxalines via a copper-catalyzed process... 

The formation of imidazoquinoxalines apparently proceeds through the tautomeric form D formed at the first stage of the reaction of the bases of Schiff C in which nucleophilic attack of atom N4 on the imine atom of carbon occurs with the closure of the imidazoline cycle the aromatization of which when exposed to the DMSO or oxygen of the air leads to the imidazo[l,5-fl]quinoxalin-4-one derivatives. 

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