Solid-state structures of 2-(4-hydroxyphenyl)-substituted phenalene-1,3-dione and indan-1,3-dione

The structure of 2-(4-hydroxyphenyl)-substituted indan-1,3-dione and phenalene-1,3-dione is investigated using a combination of solid-state NMR, single crystal X-ray analyses and quantum chemical calculations. It is shown that 2-(4-hydroxyphenyl)-1,3-indandione exists as a diketo tautomer while 2-(4-hydroxyphenyl)-1,3-phenalenedione exists in the enol form.     

Clean synthesis of 2-arylideneindan-1,3-diones in water

A high-yield synthesis of 2-arylideneindan-1,3-diones in water was achieved by the Knoevenagel condensation of indan-1,3-dione with aromatic aldehydes at ambient temperature avoiding the addition of any catalyst. The procedure is simple, efficient, as well as environmentally friendly.     

Vanillin esters in reactions with indan-1,3-dione

2-Methoxy-4-(12-oxo-12H-benzo[f]indeno[1,2-b]quinolin-13-yl)phenyl esters of carboxylic acids were synthesized by the three component condensation of indan-1,3-dione, 2-naphthylamine, and O-acylvanillin. 2-Arylidenindan-1,3-diones formed during the reaction were isolated. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, 1408–1413, September, 2006.     

Formation of carbon-carbon single bonds from isocyanates and cyclic pentaoxyphosphoranes—VI : Synthesis of 4-oxazolones and 4-thiazolones,and a new type of chapman rearrangement

The reaction of 4,5-dimethyl-2,2,2-trimethoxy-2,2-dihydro-1,3,2-dioxaphospholene with carbomethoxy, carbopropoxy and N,N-diphenylcarbamyl isocyanates yields, respectively, 2-methoxy-, 2-propoxy- and 2- diphenylamino-5-acetyl-5-methyl-2-oxazolin-4-one. The reaction with carbophenoxy isocyanate gives two products in a proportion which depends on experimental conditions: 2-phenoxy-5-acetyl-5-methyl-2-oxalin-4-one (1:1 stoichiometry) and 1,3-dicarbophenoxy-5-acetyl-5-methyl-hydantoin (1:2 stoichiometry). The 2-substituted 4- oxazolones are hydrolyzed to 5-acetyl-5-methyl-oxazolidin-2,4-dione. The alkyl group of the 2-alkoxy-4-oxazolones migrates to the adjacent nitrogen to give 3-alkyl-5-acetyl-5-methyl-oxazolidin-2,4-diones. The dioxaphospholene reacts with 2-substituted 2-thiazolin-4,5-diones to give 2-substituted 5-acetyl-5-methyl-2-thiazolin-4-ones, including rhodanine derivatives.     

Pyrimidine derivatives and related compounds. 38. Synthesis of 1,3-oxazine-2,4-diones and their reaction with nucleophiles. Ring transformation of 1,3-oxazines to pyrimidines

5,6-Unsubstituted 1,3-oxazine-2,4-diones ( 3 ) and 6-unsubstituted 5-methyl-1,3-oxazine-2,4-diones ( 4 ) were prepared by reduction of the corresponding 6-chloro derivatives ( 1 and 2 ). Treatment of 6-chloro-3-methyl-1,3-oxazine-2,4-dione ( 1a ) with sodium azide, sodium cyanide, secondary amines and aniline gave the corresponding 6-substituted compounds ( 7, 9, 10 and 11 ) while the reaction of 1a and 2a,b with primary aliphatic amines such as methylamine and ethylamine caused a ring transformation to pyrimidine ring system giving barbituric acids ( 13a-d ).     

Reaction of pyrrolo[2,1-a]isoquinoline-2,3-diones with carbon-centered nucleophiles

Knoevenagel condensations of 5,5-dimethyl-2,3,5,6-tetrahydropyrrolo[2,1-a]isoquinoline-2,3-diones with malononitrile, ethyl cyanoacetate, indan-1,3-dione, and Drotaverine base involved the ketone carbonyl group in the former with formation of deeply colored dark blue substances. The lactam ring in the products can be opened by the action of nitrogen-centered nucleophiles, e.g., p-toluidine. The reaction of 5,5-dimethyl-2,3,5,6-tetrahydropyrrolo[2,1-a]isoquinoline-2,3-dione with methyl magnesium iodide gave 2-hydroxy-2,5,5-trimethyl-2,3,5,6-tetrahydropyrrolo[2,1-a]isoquinolin-3-one.     

Three-Component Spiro Heterocyclization of Pyrrolediones with Malononitrile and Cyclic Enols

Ethyl 4,5-dioxo-2-phenyl-4,5-dihydro-1H-pyrrole-3-carboxylates reacted with malononitrile and five-membered cyclic enols, indan-1,3-dione and cyclopentane-1,3-dione to give 1-substituted ethyl 2-amino-3- cyano-2′,5-dioxo-5′-phenyl-1′,2′-dihydro-5H-spiro[indeno[1,2-b]pyran-4,3′-pyrrole]-4′-carboxylates and ethyl 2-amino-3-cyano-2′,5-dioxo-5′-phenyl-1′,2′,6,7-tetrahydro-5H-spiro[cyclopenta[b]pyran-4,3′-pyrrole]-4′-carboxylates, respectively.     

Dynamic equilibrium between dissociation and regeneration of the C-C bond in trispiro-conjoined cyclopropane compound

-The oxidation of 2,2-di(3,5-di-t-butyl-4-hydroxyphenyl)indan-1,3-dione by potassium hexacyanoferrate(III) afforded a trispiro-conjoined cyclopropane compound due to the bond formation between the ipso-carbons. Its cyclopropane ring was found to exist in solution in dynamic equilibrium with biradical species by the dissociation of the C-C bond, which is as long as 1.595 Å as revealed by X-ray crystal analysis.     

Synthesis of spirocyclic derivatives of azaphenanthrene containing a hydroxy-m-terphenyl fragment

The reaction of 5′-[(2-naphthylamino)methyl]-2′-hydroxy[1,1′:3′,1″]terphenyl with paraformaldehyde and 1,3-cyclohexanedione, methyl 2,2-dimethyl-4,6-dioxocyclohexanecarboxylate, dimedone, furan-2,4(3H,5H)-dione, indan-1,3-dione led to the formation of spiro derivatives of azaphenanthrene.     

Synthesis of exo- and endocyclic enamino derivatives of 2-(3-arylprop-2-enoyl)cyclohexane-1,3-diones

Condensation of 2-acetylcyclohexane-1,3-diones with aromatic aldehydes in the presence of piperidine, pyrrolidine, hexamethyleneimine, or morpholine gave the corresponding 2-(3-arylprop-2-enoyl)cyclohexane-1,3-diones as the major products and 2-[3-aryl-1-cycloalkylaminoprop-2-en-1-ylidene]cyclohexane-1,3-diones as minor ones. Endocyclic enamino derivatives were synthesized in two steps through enol methyl ethers which reacted with amines. Endocyclic enamino derivatives of 2-(3-arylprop-2-enoyl)cyclohexane-1,3-diones containing an aryl group on the nitrogen atom readily underwent cyclization to 1,2,3,4,5,6,7,8-octahydroquinoline-4,5-dione derivatives.     

Neuartige Merocyanine vom Typ des «Bindons»

The title compounds (new type of merocyanines) were obtained from the reaction of heterocyclic enamines with indan-1,3-dione, biindantrione, 2-(3-methoxy-inden-1-yliden)-indan-1, 3-dione, or 2-(3-chloro-inden-1-yliden)-indan-1, 3-dione respectively. The enamines were obtained from the corresponding quaternary salts and reacted in situ.     

Photocyclization of 2-chloro-substituted 1,3-diarylpropan-1,3-diones to flavones

The photochemical behavior of 2-halo-substituted 1,3-diarylpropan-1,3-dione strongly depends on the nature of the halogen atom bonded and the presence of electron-donor groups on the phenyl ring. In the case of 2-chloro-1,3-diphenylpropan-1,3-dione and 1-(3,5-dimethoxyphenyl)-3-phenylpropan-1,3-dione, cyclization to flavones was the sole reaction pathway, whereas in the case of 2-chloro-1,3-di(4-methoxyphenyl)propan-1,3-dione, only products derived from alpha-cleavage were observed. 2-Fluoro derivatives of 1,3-diarylpropan-1,3-diones were photostable; on the other hand, 2-chloro-2-fluoro derivates resulted in 3-fluoroflavones.     

Structure of azaindan-1,3-diones in solution

It is shown spectrophotometrically that 2-phenylazaindan-1,3-diones can give in solution a cation, a dipolar ion and an anion, and the protolysis constants of the forms of 2-phenyl-4-azaindan-1,3-dione and 2-phenyl-5-azaindan-1,3-dione are found.     

Fluorinated 2-benzoylcyclohexane-1,3-diones and their vinylogous acyl chlorides in the reactions with primary and secondary amines

The reaction of 5,5-dimethyl-2-[(3-fluoro- and 4-fluoro)benzoyl]cyclohexane-1,3-diones with primary and secondary amines affords their exocyclic enamine derivatives. Under similar conditions 5,5-dimethyl-2-(2-fluorobenzoyl)]cyclohexane-1,3-dione undergoes dehydrofluorination and intramolecular cyclization to give 3,3-dimethyl-2,3,4,9-tetrahydro-1H-xanthene-1,9-dione. The reaction of vinylogous substitution of the enol derivatives of the fluorinated 5,5-dimethyl-2-benzoylcyclohexane-1,3-diones (vinylogous acyl chlorides) with amines results in the formation of the endocyclic enaminoderivatives.     

Functiaonalization of 2-(1-Cyclohexen-1-yl)aniline Derivatives

The reaction of 2-(1-cyclohexen-1-yl)aniline and -6-methylaniline with phthalic anhydride has afforded 2-(2-cyclohex-1-en-1-ylphenyl)- and 2-(2-cyclohex-1-en-1-ylphenyl)-6-methylphenyl)-1H-isoindole-1,3(2H)-diones. The reaction of the obtained isoindole-1,3-diones with bromine in dichloromethane in the presence of sodium bicarbonate has led to the formation of the product of pseudo-allylic halogenation. Replacement of the halogen atom by methoxy group has been performed by keeping 2-[2-(6-bromocyclohex-1-en-1-ylphenyl)-6-methylphenyl)]-1H-isoindole-1,3(2H)-dione in a methanolic solution in the presence of NaHCO₃. The reaction of 2-(2-cyclohex-1-en-1-yl-6-methylphenyl)-1H-isoindole-1,3(2H)-dione with molecular bromine in the presence of methanol has given a co-halogenation product, whereas the dibromination product has been obtained in the presence of octyl alcohol.

     

Reaction of 5-Substituted 4-(Trufluoroacetyl)furan-2,3-diones with Schiff Bases

In reaction of trifluormethyl-containing 1,3-diketones with oxalyl chloride 5-substituted 4-(trifluoracetyl)furan-2,3-diones were synthesized, reaction of which with azomethines resulted in 4-substituted 5-hydroxy-5-(trifluormethyl)dihydrofuran-2,3-diones.     

Synthesis of 1H-naphth[2,3-d]imidazole-4,9-diones by acid catalyzed cyclization of 2-Acylamino-3-amino-1,4-naphthoquinones

The conversion of 2-acylamino-3-amino-1,4-naphthoquinones (II) to the corresponding 2-substituted 1H-naphth[2,3-d]imidazole-4,9-diones (I) under both alkaline and acid catalyzed conditions has been effected and the results compared. Treatment of 3-(4′-chlorobutanonyl-amino)-3-amino-1,4-naphthoquinone (He) with aqueous ethanolic sodium hydroxide solution gives 1,2-butanonaphth[2,3-d]imidazole-4,9-dione (V); whereas, treatment of lie with refluxing formic acid gave 2-(4′-chlorobutyl)-1H-naphth[2,3-d]imidazole-4,9-dione. Treatment of 2-substi-tuted 1H-naphth[2,3-d]imidazole-4,5-diones in DMF with alkyl halides in the presence of potassium carbonate affords the expected 1,2-disubstituted naphth[2,3-d]imidazole-4,9-diones (VI). The spectral properties of I, II, V and VI as well as those of some 2-acylamino-3-chloro-1,4-naphthoquinones IV are discussed.     

Comparative reductive desymmetrization of 2,2-disubstituted-cycloalkane-1,3-diones

Reductive desymmetrization of 2-methyl-2-substituted-cycloalkane-1,3-diones can be effected using either NaBH₄ in DME or lithium tri-tert-butoxyaluminum hydride (LTBA) in THF at −60 °C. The former is a new approach that offers slightly greater diastereoselectivity in the reduction of 2,2-disubstituted-cyclopentane-1,3-diones while LTBA is superior with 2,2-disubstituted-cyclohexane-1,3-diones. Both conditions minimize subsequent reduction to diols thereby furnishing high yields of 1,3-ketols. Particularly rapid monoreductions are observed with 2-methyl-2-nitroethylcyclopentane-1,3-dione and 2-cyanoethyl-2-methylcyclopentane-1,3-dione when treated with NaBH₄ in DME at −60 °C. As expected, diastereoselectivity varies considerably with the substitution at C-2.     

2-perfluoroalkanoylcyclopentane-1,3-diones. Synthesis and some transformations

2-Perfluoroalkanoylcyclopentane-1,3-diones were synthesized for the first time by acylation of cyclopentane-1,3-dione with perfluorocarboxylic acids in the presence of 1,1??-carbonyldiimidazole or with perfluorocarboxylic anhydrides in the presence of imidazole. 2-Perfluoroalkanoylcyclopentane-1,3-diones were selectively reduced to 2-(1-hydroxyperfluoroalkyl)cyclopentane-1,3-diones by the action of triethylsilane in trifluoroacetic acid in the presence of a catalytic amount of lithium perchlorate. Treatment of the title compounds with oxalyl chloride and subsequent reaction with 2 equiv of primary amine (4-fluoroaniline, 4-fluorobenzylamine, 3,4-difluoroaniline, 3-trifluoromethylbenzylamine) gave the corresponding 3-arylamino-2-perfluoroalkanoylcyclopent-2-en-1-ones.     

Synthesis of 1-(oxiran-2-ylmethyl)-1<Emphasis Type="Italic">H</Emphasis>-indole-3-carbaldehyde and its transformation into amino alcohols containing an indan-1,3-dione fragment

A procedure for the synthesis of 1-(oxiran-2-ylmethyl)-1H-indole-3-carbaldehyde was developed and optimized. Its reaction with indan-1,3-dione, followed by treatment with amines, afforded 1,2-amino alcohols containing an indole fragment.