One-pot synthesis of benzo[f]quinolin-3-ones and benzo[a]phenanthridein-5-ones by the photoanuulation of 6-chloropyridin-2-ones and 3-chloroisoquinolin-1-ones to phenylacetylene

The one-pot synthesis of benzo[f]quinolin-3-ones and benzo[a]phenanthridein-5-ones was achieved by the inter- and intramolecular photoannulation of 6-chloropyridin-2-ones and 3-chloroisoquinolin-1-ones with phenylacetylene or tethered phenylacetylene. The reactions were proceeded by photoaddition of 6-chloropyridin-2-ones and 3-chloroisoquinolin-1-ones to phenylacetylene to give the chlorine-substituted stilbenoids, and then 6π electrocyclization of the stilbenoids and oxidation aromatization to afford the polycyclic products.     

A novel route to substituted 3-methylidenechroman-2-ones and 3-methylchromen-2-ones

3-Methylidenechroman-2-ones, or their rearrangement products 3-methylchromen-2-ones, were efficiently synthesized by Michael addition of various nucleophiles to 3-diethoxyphosphorylchromen-2-ones followed by Horner-Wadsworth-Emmons reaction of the adducts with formaldehyde. Relative configuration and conformation of the intermediate adducts were studied using NMR spectroscopy and semiempirical PM3 calculations.     

A convenient synthesis of 1,3-oxazolidin-4-ones and 1,3-oxazin-4-ones

1,3-Oxazolidin-4-ones and 1,3-oxazin-4-ones were synthesized by formal cyclocondensation of imines with α- or β-hydroxy acids.     

Synthesis of New Substituted 2,3-Dihydro-1,4-dioxin-2-ones and 1,4-Dioxan-2-ones

3-Alkyl-6-methyl-2,3-dihydro-1,4-dioxin-2-ones reacted with acetyl chloride in the presence of zinc(II) chloride to give the corresponding 3-alkyl-5-acetyl-6-methyl-2,3-dihydro-1,4-dioxin-2-ones. Oxidation of the latter with hydrogen peroxide in formic acid, followed by treatment with magnesium bromide, afforded 3-alkyl-6-methyl-1,4-dioxane-2,5-diones. Successive chlorination and dechlorination of 6-hydroxymethyl-1,4-dioxan-2-ones yielded 6-methylene-1,4-dioxan-2-ones.     

Bromination of 5-Substituted 3H-Furan-2-ones and 3H-Pyrrol-2-ones

The bromination of 5-alkyl(aryl)-3H-furan-2-ones and 5-alkyl(aryl)-3H-pyrrol-2-ones and also their derivatives takes place at the ethylene bond with the formation of 4-monobromo derivatives. N-Phenyl-3H-pyrrol-2-ones are brominated simultaneously at the ethylene bond of the heterocycle and at the phenyl substituent at the nitrogen atom.     

Synthesis of New Substituted 2,3-Dihydro-1,4-dioxin-2-ones and 1,4-Dioxan-2-ones

3-Alkyl-6-methyl-2,3-dihydro-1,4-dioxin-2-ones reacted with acetyl chloride in the presence of zinc(II) chloride to give 5-acetyl-3-alkyl-6-methyl-2,3-dihydro-1,4-dioxin-2-ones. Oxidation of the latter with hydrogen peroxide in formic acid, followed by treatment with magnesium bromide, afforded 3-alkyl-6-methyl-1,4-dioxane-2,5-diones. Chlorination of 6-hydroxymethyl-1,4-dioxan-2-ones with thionyl chloride and subsequent dehydrochlorination led to formation of 6-methylene-1,4-dioxan-2-ones.     

Concurrent alkylation-methoxylation of 4,5-dihalopyridazin-6-ones and synthesis of 5-halo-4-hydroxypyridazin-6-ones

1-Alkyl-5-halo-4-methoxypyridazin-6-ones were synthesized from 1-alkyl-4,5-dihalopyridazin-6-ones by the concurrent alkylation-methoxylation. 1-Alkyl-5-halo-4-hydroxypyridazin-6-ones were also prepared.     

Recent development in the synthesis of pyrrolin-4-ones/pyrrolin-3-ones

Pyrrolin-4-ones/pyrrolin-3-ones and its derivatives are important heterocyclic systems which are observed in vast variety of natural products, pharmaceuticals, and biologically important compounds. Different researchers all across the world have developed different synthetic methodologies for the construction of functionalized pyrrolin-4-ones/pyrrolin-3-one scaffolds such as the transition-metal catalyzed/mediated cycloisomerizations of 1-aminoynones and dimerization of enaminones or α-diazo-β-oxoamides etc. The present review article summarizes various reports on the synthesis of various simple and functionalized pyrrolin-4-ones/pyrrolin-3-ones from 2000 onward.     

On the characterization of dihydro-oxazin-6-ones and N-acetylazetidin-2-ones by mass spectrometry

Mass spectrometry has been used in an attempt to resolve the ambiguity in the structures of the isomeric dihydro-oxazin-6-ones and N-acyl-azetidin-2-ones.     

Synthesis of imidazolidin-4-ones and their conversion into 1,4-benzodiazepin-2-ones

α-Haloacetanilides Ia-e react with hexamine in ethanol giving the bisimidazolidin-4-one derivatives IIa-e, which hydrolize, in acidic media into the corresponding mono-imidazolidin-4-ones IIIa-e. The compounds IIa-d were converted into 1,4-benzodiazepin-2-ones, under different conditions and in the presence of a variety of agents. The yields were between 50 and 100%.     

1,2,3,5-Tetrahydro-4H-1,5-benzodiazepin-4-ones and 1,2,3,4-tetrahydro-5H-1,4-benzodiazepin-5-ones from the reaction of hydrazoic acid on 1,2,3,4-tetrahydroquinolin-4-ones

The Schmidt reaction on 1,2,3,4-telrahydroquinolin-4-ones (1) gave 1,2,3,5-telrahydro-l,5-benzodiazepin-4-ones (II) and 1,2,3,4-tetrahydro-1,4-benzodiazepin-5)-ones(III). The ratio of II and III is dependent upon substituents present on the nitrogen ring atom of the quinolinones.     

Efficient syntheses of 3-phosphorylquinolin-4-ones and 3-phosphoryl-1,8-naphthyridin-4-ones

A series of 3-diethoxyphosphorylquinolin-4-ones and 3-diethoxyphosphoryl-1,8-naphthyridin-4-ones containing various substituents at N-1 and C-7 was synthesized in a four-step reaction sequence starting from readily available ethyl 2-chlorobenzoates or ethyl 2-chloronicotinates and diethyl methylphosphonate. Selected quinolinone and naphthyridinone products were transformed into free mono and diacids.     

Parallel synthesis of 3-amino-4H-quinolizin-4-ones, fused 3-amino-4H-pyrimidin-4-ones, and fused 3-amino-2H-pyran-2-ones

On the basis of the enaminone methodology, libraries of 3-amino-4H-quinolizin-4-ones, fused 3-amino-4H-pyrimidin-4-ones, and fused 3-amino-2H-pyran-2-ones were synthesized by the solid-phase and by the solution-phase parallel synthesis. The solution-phase approach turned out to be advantageous over the solid-phase approach. The solution-phase synthesis afforded, in most cases, analytically pure products in high yields, whereas the solid-phase approach gave products in poor yields and in low purity.     

1,4,5,6-Tetrahydro-1,2,4-triazin-6-ones and 3-amino-1-imidazolin-4-ones from 2-aminoacylhydrazines

The 2-aminoacylhydrazines form 1,4,5,6-tetrahydro-1,2,4-triazin-6-ones with orthoesters and iminoesters. Benzylidene and isopropylidene derivatives of the 2-aminoacylhydrazines give the corresponding derivatives of 3-amino-1-imidazolin-4-ones with the same reagents.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1388–1391, October, 1991.     

Nitrosochlorination reaction of substituted imidazolin-2-ones

Interaction of nitrosyl chloride with 1-arylimidazolin-2-ones in methanol leads to the formation of 4,5-dimethyoxyimidazolidin-2-ones. Under similar conditions 1,5-diarylimidazolin-2-ones give 1,5-diaryl-4-oximino-5-alkoxyimidazolidin-2-ones. When the reaction is carried out in an aprotic solvent 1,5-diaryl-4-nitrosoimidazolin-2-ones are separated, and when treated with alcohol they give the final reaction products. An increase in temperature and duration of the reaction results in the formation of 1,5-diaryl-5-hydroxyhydantoins.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1339–1342, October, 1986.     

The synthesis of isoindolin-3-ones,Phthalazin-4(3H)-ones and related systems

The reaction between methyl 2-cyanobenzoate and its pyridine analogues gave isoindolin-3-ones, phthalazin-4(3H)-ones and their corresponding aza analogues. Some reactions of 1-benzylaminoiminoisoindolin-3-one 5b were investigated.     

Acylation of 1-arylpyrazolidin-3-ones

Acylation of 1-arylpyrazolidin-3-ones using aromatic acid anhydrides and chlorides in the presence of base occurs principally at the oxygen atom to give 1-aryl-3-acyloxy-2-pyrazolines, subsequent heating or microwave irradiation of which leads to the corresponding N-acylpyrazolidin-3-ones. The action of aliphatic acid anhydrides and chlorides on 1-arylpyrazolidin-3-ones gives predominantly the N-acylpyrazolidin-3-ones.M. V. Lomonosov State University, Moscow 119899, Russia. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 634–639, May, 2000.     

One-pot synthesis of benzo[a]phenanthridin-5-ones by photoinduced cycloaddition of 3-chloroisoquinolin-1-ones with styrenes

One-pot synthesis of benzo[a]phenanthridin-5-ones and benzo[k]phenanthridin-6-ones in fairly good yields was achieved by the photocycloaddition reactions of 3-chloroisoquinolin-1-ones and 3-chloroquinolin-2-ones with styrenes. The reactions were proceeded via photoinduced dechlorinative coupling of 3-chloroisoquinolin-1-ones and 3-chloroquinolin-2-ones with styrenes and subsequent photocyclization, oxidative aromatization.     

Parallel microwave-assisted library of imidazothiazol-3-ones and imidazothiazin-4-ones

A methodology for the generation of a microwave-assisted parallel library and its conversion into a second library is described. A 24-membered library of substituted 4(5)-sulfanyl-1H-imidazoles was generated and subsequently converted into a second library of bicyclic imidazo[5,1-b]thiazol-3-ones and imidazo[5,1-b]thiazin-4-ones. The first library was generated using a three-component reaction and transformed into a daughter library with a polymer-supported coupling agent. The procedure involved the use of an array of expandable reaction vessels, which can accommodate pressure buildup due to microwave heating without loss of volatile solvents or reagents. Library generation time for each library was 16 min.     

Substituted dienic 1,3-dioxolan-2-ones and bis(1,3-dioxolan-2-ones)

Alkylthio-substituted dienic 1,3-dioxolan-2-ones and bis(4,4-diorganyl-5-methyli-dene-1,3-dioxolan-2-ones) were obtained in high yields by the reaction of 2-methyl-6-alkylthio-5-hexen-3-yn-2-ols and tertiary diacetylenic glycols with carbon dioxide under pressure in the presence of catalytic amounts of triethylamine and monovalent copper salts.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1617–1619, December, 1979.Original article submitted January 24, 1979.