Synthesis of 2-aryl-oxazolo[4,5-c]quinoline-4(5H)-ones and 2-aryl-thiazolo[4,5-c]quinoline-4(5H)-ones

[reaction: see text] Novel and highly efficient syntheses of oxazolo[4,5-c]quinoline-4(5H)-ones (1) and thiazolo[4,5-c]quinoline-4(5H)-ones (2) from ethyl 2-chlorooxazole-4-carboxylate (4) and ethyl 2-bromo-5-chlorothiazole-4-carboxylate (13), respectively, are described.     

Synthesis of 3,5-Disubstituted-4,5-dihydroindeno[1,2-c] [1,2]diazepin-6(1H)-ones

3,5-Disubstituted 4,5-dihydroindeno[1,2-c][1,2]diazepin-6 (1H)-ones ( 3a–g ) were obtained in 29–72% yields by condensing 2-(substituted-2-acylethyl)-1,3-indandiones ( 1a–n ) with hydrazine. The NH group of the indenodiazepinones 3a–g is quite unreactive. Two methods based on the Michael reaction were used for preparing the acylethylindandiones 1a–n : one from 1,3-indandione and chalcone-type compounds and the other from 2-benzylidene-1,3-indandione and acetophenones. The latter method was found more practical and of more general application.     

Visible-Light-Driven Sulfonylation/Cyclization to Access Sulfonylated Benzo[4,5]imidazo[2,1-a]isoquinolin-6(5H)-ones

Visible-light-driven sulfonylation/cyclization of N-methacryloyl-2-phenylbenzoimidazoles has been successfully developed. Using commercially available sulfonyl chloride as sulfonylation reagent, a wide range of sulfonylated benzo[4,5]imidazo[2,1-a]isoquinolin-6(5H)-ones with potential antitumor activity were provided in acceptable to excellent yields. This method has the advantages of mild reaction conditions and outstanding functional group tolerance, and provides a new strategy for the development of potential antitumor lead compounds.     

Synthesis of imidazo[4,5-c]quinolin-4(5H)-one via radical cyclization

The tributyltin radical-induced cyclization of N-(2-bromophenyl)-Nbutyl-1H-1-methylimidazole-4-carbox-amide 3 gave 5-butyl-3-methyl-3H-imidazo[4,5-c]quinolin-4(5H)-one 5 via [1,2]-acyl rearrangement.     

Synthesis and some reactions of 4-nitro derivatives of imidazo[4,5-c]pyridin-2-ones

Imidazo[4,5-c]pyridine and its N-methyl derivatives do not undergo nitration, but the 2-oxo derivatives of these compounds are easily nitrated when heated. Some properties of the resulting 4-nitroimidazo[4,5-c]pyridin-2-ones have been studied.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 97–102, January, 1986.     

One-Pot Synthesis of Benzo[4,5]imidazo[1,2-a]pyrimidin-2-ones Using a Hybrid Catalyst Supported on Magnetic Nanoparticles in Green Solvents

The conversion of soluble polyoxometalate into insoluble polyoxometalate is considered to be one of the major challenges in synthetic organic chemistry. Here, polyoxometalate was bonded to the salt part of an organic branch immobilized on the silica-coated Fe₃O₄ nanoparticle and characterized using various techniques. The fabricated complex was used as a heterogeneous catalyst in a novel one-pot reaction for synthesis of benzo[4,5]imidazo[1,2-a]pyrimidin-2-ones using aromatic amines, dimethyl acetylenedicarboxylate (DMAD), derivatives of benzaldehyde and 2-aminobenzimidazole in water/ethanol as a green solvent. 21 derivatives of benzo[4,5]imidazo[1,2-a]pyrimidin-2-one were synthesized by this method and fully characterized. The high stability of the catalyst showed that it can be reused for 6 times without decreasing in activity. The combination of new synthetic method, new ferromagnetic heterogeneous nano-catalyst, green solvent and simple separation method were presented in this work.     

1-Substituted 5,10-Dihydro[1,2]diazepino[4,5-b]indol-4(3H)-ones. Synthesis and Functionalization

Russian Journal of Organic Chemistry - A number of new 1-substituted 5,10-dihydro[1,2]diazepino[4,5-b]indole-4(3H)-ones were synthesized, and their structural modification was performed to obtain...     

Visible-light-induced photoredox-catalyzed synthesis of benzimidazo[2,1-a]iso-quinoline-6(5H)-ones

A simple and efficient visible-light-induced photoredox-catalyzed diarylation of N-methacryloyl-2-arylbenzoimidazoles with aryl diazonium salts was developed. The reaction provides a convenient access to a variety of benzimidazoisoquinolinones through the construction of two CC bonds in one step under mild reaction conditions.     

Synthesis of 7-substituted imidazo[1,2-a]pyrimidin-5(1H)-ones

The synthesis of 7-substituted imidazo[1,2-a]pyrimidin-5(1H)-ones by either of 2 methods is reported.     

New bronchodilators. II. 3H-imidazo[4,5-c]quinolin-4(5H)-ones.

A series of novel 3-substituted imidazo[4,5-c]quinolin-4(5H)-ones (2a-w) was prepared by the reaction of imidazo[4,5-c]quinolin-4(5H)-ones (6) with several electrophiles under basic conditions. The bronchodilatory activity of these compounds was evaluated on the basis of their protective effects against antigen-induced contraction (the Schultz-Dale reaction) of guinea-pig trachea (in vitro) and antigen inhalation-induced bronchospasm in passively sensitized guinea-pigs (in vivo). Although correlations between in vitro and in vivo activities were not clear, short alkyl chains such as the methyl and ethyl groups at the 3-position were important for potent activity, especially in vivo. Substituents at the 5-position were more tolerant of the activity than those at the 3-position. 5-Ethyl-3-methyl-3H-imidazo[4,5-c]quinolin-4(5H)-one (21) exhibits the most potent bronchodilatory activity among our tested compounds and is at least 5-fold more active than theophylline in vivo.     

Green and Catalyst-Free Synthesis of Some New Benzo[4,5]imidazo[1,2-a]pyrimidine Derivatives as Antimicrobial and Antitubercular Agents

Russian Journal of Organic Chemistry - A new series of 4-(1H-imidazol-4-yl)-2-(substituted phenyl)-1,4-dihydrobenzo[4,5]imidazo[1,2-a]­pyrimidines have been synthesized via a one-pot reaction...     

Synthesis of some new imidazo[1,2-a]pyrimidin-5(1H)-ones as potential antineoplastic agents

Some substituted imidazo[1,2-a]pyrimidin-5(1H)-ones have been synthesized via the reaction of 2-aminoimidazole sulfate with some β-keto esters, diethyl ethoxymethylenemalonate and ethyl ethoxymethylenecyanoacetate. Several compounds were screened for their in vitro antineoplastic and anti-HIV activity but were inactive.     

Synthesis of 4,5-dihydro-1H,3H-thieno[3,4-c]thiophene and 4,5-dihydro-1H,3H-thieno[3,4-c]furan

4,5-Dihydro-1H,3H-thieno[3,4-c]thiophene and 4,5-dihydro-1H,3H-thieno[3,4-c]furan were synthesized by retro Diels-Alder reactions under flash vacuum thermolysis conditions.     

4-Hydroxy-2-quinolones. 36. Synthesis of 2-R-oxazolo[4,5-c]quinolin-4(5H)-ones

We consider different variants for synthesis of 2-R-oxazolo[4,5-c]quinolin-4(5H)-ones based on 3-amino-1H-2-oxo-4-hydroxyquinolines and their 3-N-acyl derivatives. We show, that in the latter case, formation of the oxazole ring is possible via two routes, depending on the nature of the substituent on the acyl residue. For Communication 35, see [1]. Ukrainian Pharmaceutical Academy, Kharkov 310002. Translated from Khimiya Geterotsiklicheskikh Soedinenii. No. 11. pp. 1536–1541, November, 1997.     

Quino[1,2-c]quinazolines. II. Synthesis of 12,13-dihydro-11bH-quino-[1,2-c]quinazolines via the versatile intermediates 2-(2-amino-4,5-dimethoxyphenyl)-6,7-disubstituted-1,2,3,4-tetrahydroquinolines

The versatile intermediates 2-(2-amino-4,5-dimethoxyphenyl)-6,7-dimethoxy-1,2,3,4-tetrahydroquinoline ( 2a ) and 6-(2-amino-4,5-dimethoxyphenyl)-5,6,7,8-tetrahydro[1,3]dioxolo[4,5-g]quinoline ( 2b ) were used in the preparation of a wide variety of 12,13-dihydro-11bH-quino[1,2-c]quinazolines by reaction with triethyl orthoformate, cyanogen bromide, urea and carbon disulfide in pyridine. Reaction of the thio and keto products with methyl iodide and phosphorus oxychloride, respectively, gave the requisite methylthio and chloro derivatives. Novel Reissert type reactions occurred when the intermediates 2a,b were reacted with acetic anhydride or benzoyl chloride. The attempted dehydrogenation of 12,13-dihydro-2,3,9,10-tetramethoxy-11bH-quino[1,2-c]quinazoline ( 3a ) is also reported.     

Synthesis of 3-(Dialkylamino)-4-halofuro[3,4-c]pyridin-1(3H)-ones

Russian Journal of Organic Chemistry - The reaction of 4-halo-3-hydroxyfuro[3,4-c]pyridin-1(3H)-ones with acyclic and alicyclic secondary amines in ethyl acetate afforded the corresponding...     

Synthesis of 2-Phosphono Alkyl 1,2-Benzisoselenazol-3(2H)-ones

A series of 2-phosphonoalkyl 1,2-benzisoselenazol-3(2H)-ones were designed and synthesized via reaction 2-chloroselenobenzoyl chloride with 1-hydrazinobenzyl phosphonate. The structures of all new compounds were confirmed by spectroscopic methods and microanalyses.     

Synthesis,antimicrobial, and mitotic toxicity evaluation of new 6-substituted 2-(benzo[4,5]imidazo[1,2-c]quinazolin-5(6H)-yl)acetic acids

A series of novel 6-substituted 2-(benzo[4,5]imidazo[1,2-c]quinazolin-5(6H)-yl)acetic acids were synthesized and characterized by ¹H, ¹³C, ¹⁹F NMR, ¹H-¹H-COSY, ¹H-¹³C-HSQC, NOESY, LC-MS, IR, and elemental analysis. The mitotic toxicity of the synthesized compounds was determined according to the Allium test procedure. The 2-(6-(pentafluorophenyl)benzo[4,5]imidazo[1,2-c]quinazolin-5(6H)-yl)acetic acid inhibited mitotic spindle formation, which resulted in significant cytotoxic effect for meristematic cells of Allium cepa l . roots. In a preliminary antimicrobial evaluation, only Streptococcus pyogenes and Candida albicans were slightly susceptible to some of the synthesized compounds.