3-acyl-1,5-benzodiazepines in the reactions of 5,5-dimethyl-2-formylcyclohexane-1,3-dione with certain 1,2-diaminobenzenes

Reaction of 5,5-dimethyl-2-formylcyclohexane-1,3-dione with 4-methyl-, 4-benzoyl-, and 4-nitro-1,2-diaminobenzenes gave the corresponding 2-(2-amino-4-methylphenylaminomethylene)-, 2-(2-amino-5-benzoylphenylaminomethylene)-, and 2-(2-amino-5-nitrophenylaminomethylene)-5,5-dimethylcyclohexane-1,3-diones. When treated with hydrochloric acid, they cyclize to 7-methyl-, 8-benzoyl-, and 8-nitro-3,3-dimethyl-2,3,4,5-tetrahydro-1H-dibenzo[b,e][1,4]diazepinon hydrochlorides. Under hydrolytic conditions the salts of 3,3,7-trimethyl-2,3,4,5-tetrahydro-1H-dibenzo[b,e][1,4]diazepinone and 3,3-dimethyl-2,3,4,5-tetrahydro-1H-dibenzo[b,e][1,4]diazepinone undergo the C₁₁−N₁₀ bond cleavage to give N-(2-aminophenyl)- and N-(2-amino-5-methylphenyl)-substituted 3-amino-2-formyl-5,5-dimethylcyclohex-2-enones. Ring opening of the hydrochlorides of 8-benzoyl-, and 3,3-dimethyl-8-nitro-2,3,4,5-tetrahydro-1H-dibenzo[b,e][1,4]diazepinones occurs at the C−N₅ bond and gives the starting enamines. Riga Technical University, Riga LV-1658, Latvia; Translated from Khimiya Geterotsiklicheskikh Soedinenii, N. 5, pp. 696–700, May, 1999.     

Reactions of zinc enolates derived from 1-Aryl-2-bromo-alkanones with 3-acyl-6-bromochromen-2-ones

Zinc enolates derived from 1-aryl-2-bromoalkanones react with 3-acyl-6-bromochromen-2-ones to give 3-acetyl(benzoyl)-6-bromo-4-(2-aryl-2-oxo-1-R-ethyl)chromen-2-ones as a single diastereoisomer.Translated from Zhurnal Organicheskoi Khimii, Vol. 40, No. 10, 2004, pp. 1536–1538.Original Russian Text Copyright © 2004 by Shchepin, Korzun, Shurov, Vakhrin.     

Synthesis of polyfunctionalized furans from 3-acetyl-1-aryl-2-pentene-1,4-diones

The BF₃-catalyzed cyclization of 3-acetyl-1-aryl-2-pentene-1,4-diones 1a-e in the presence of water in boiling tetrahydrofuran gave bis(3-acetyl-5-aryl-2-furyl)methanes 2a-e in 26-79% yields along with a small amount of 3-acetyl-5-aryl-2-methylfurans 3a-e. The exact structure of 2a was determined by X-ray crystallography. The use of a half volume of the solvent for the reaction of 1a resulted in the formation of 2,4-bis(3-acetyl-5-phenyl-2-furfuryl)-3-acetyl-5-phenylfuran (4) together with 2a and 3a. A similar reaction of 1a was carried out in the presence of 3-acetyl-5-(4-methylphenyl)-2-methylfuran (3d) to afford 4-(3-acetyl-5-phenyl-2-furfuryl)-3-acetyl-5-(4-methylphenyl)-2-methylfuran (5) in 49% yield. The BF₃-catalyzed reaction of 1a with 2,4-pentanedione in dry tetrahydrofuran at 23°C gave 3-(3-acetyl-5-phenyl-2-furfuryl)-4-hydroxy-3-penten-2-one (6a) and 3-(3-acetyl-2-methyl-4-phenyl-5-furyl)-4-hydroxy-3-penten-2-one (7a) in 66 and 24% yields, respectively. The product distribution depended on the reaction temperature. A similar reaction of 1b-e also yielded the corresponding trisubstituted furans 6b-e and tetrasubstituted furans 7b-e in good yields. These results suggested the presence of the furfuryl carbocation intermediate A during the reaction. The one-pot synthesis of 6a and 7a was also achieved by a similar reaction using phenylglyoxal. The deoxygenation of 1a with triphenylphosphine gave 3a in 88% yield, while 1a was treated with concentrated hydrochloric acid to yield 3-acetyl-2-chloromethyl-5-phenylfuran (8) which was quantitatively transformed in ethanol into 3-acetyl-2-ethoxymethyl-5-phenylfuran (9) and in water into 3-acetyl-5-phenylfurfuryl alcohol (10), respectively. In addition, the Diels-Alder reaction of cyclopantadiene with 1a gave the corresponding [4+2] cycloaddition products 11 and 12.     

Pyridinethiones. XV. 3-Methylthio-2-pentene-1,5-diones as synthons for 4-methylthio-2(1H)-pyridinethiones,and synthesis of 4-methylene-1,4-dihydropyridines

Starting from α-oxoketene dithioacetals the 3-methyithio-1,5-pentenedione enolates 4 obtained from ketones 3 give 4-methylthio-2(1H)-pyridinethiones with isothiocyanates. Enolates 4 can be alkylated with methyl iodide at C-2, giving 5-methyl-4-methylthio-2-(1H)-pyridmethiones with isothiocyanates. The S-alkylated pyridinethiones react with the anion of malodinitrile, giving 4-(1,1-dicyanomethylene)-1,4-dihydropyridines.     

Five-membered 2,3-dioxo heterocycles. 2. Synthesis and [1,5]-sigmatropic rearrangement of 4-acyl-3-diphenylmethoxy-1,5-diphenyl-2,5-dihydropyrrol-2-ones

4-Acyl-1,5-diphenyltetrahydropyrrole-2,3-diones react with diphenyldiazomethane to give O-alkylation products, which upon heating undergo [1,5]-sigmatropic suprasurface rearrangement to form 4-[methyl- and 4-[-aryl(diphenylmethoxy)-methylene]-1,5-diphenyltetrahydropyrrole-2,3-diones.See [1] for Communication 1.Translated from Khimiya Geterotsiklicheskikh Soedinenii. No. 5, pp. 625–628, May, 1987.     

Acid catalyzed cope rearrangements of 2-acyl-1,5-dienes

The Cope rearrangement of 1,5-dienes bearing acyl substituents in the 2-position of the diene system is strongly accelerated by protic and Lewis acids.     

Synthesis of 3,4,7,8-tetrahydronaphthalene-1,5(2H,6H)-dione

A short and high yielding route for the preparation of the title compound, starting from commercially available 1,5-dihydroxynaphthalene, is described. The key step in the sequence is the air oxidation of a bis(trimethylsilyloxy)diene precursor.     

Synthesis of 2,3-Dihydrothiopyran-4-ones from 3-Oxo-1-pentene-4-ynes

3-Oxo-1-pentene-4-ynes were converted with sodium sulfide or hydrogensulfide to give 2,6-disubstituted 2,3-dihydrothiopyran-4-one derivatives. The starting materials were prepared in two steps from terminal alkynes and α,β-unsaturated aldehydes.     

2-氰基-3-甲硫基-3-取代甲氨基丙烯酸酯类化合物的合成及其除草活性

A series of 2-cyano-3-methylthio-3-substituted methylaminoacrylates were synthesized as herbicidal inhibitors of photosystem Ⅱ （PSⅡ） electron transport, in order to estimate the effect of fluorine atom, pyridyl group, chirality and ester chain on activity. The important intermediate 2-fluoro-5-aminomethylpyridine was synthesized with high yield. The bioassay results showed that most of rifle compounds had high herbicidal activity in postemergence treatment. The introduction of an a-methyl into the 3-substituted methylamino could improve the activity notably. The replacement of hydrogen by chlorine or fluorine group and phenyl by pyridyl group showed different effects, and at the same time, the ester chain affected the activity too.     

Synthesis of 2,3-Dihydrothiopyran-4-ones from 3-Oxo-1-pentene-4-ynes

Summary. 3-Oxo-1-pentene-4-ynes were converted with sodium sulfide or hydrogensulfide to give 2,6-disubstituted 2,3-dihydrothiopyran-4-one derivatives. The starting materials were prepared in two steps from terminal alkynes and α,β-unsaturated aldehydes.     

Reactivity of (2-alkenyl-3-pentene-1,5-diyl)iron complexes: preparation of functionalized vinylcyclopropanes and cycloheptadienes

The reactivity of (2-alkenyl-3-pentene-1,5-diyl)iron complexes toward olefin metathesis, cycloaddition, and mild oxidations (MnO 2 or mCPBA) was examined. Cycloaddition reactions were observed to occur with modest diastereoselectivity (33-63% de). Decomplexation of the (3-pentenediyl) ligand may be accomplished by oxidation with either CAN or alkaline hydrogen peroxide to afford vinylcyclopropanecarboxylates or divinylcyclopropanecarboxylates. Reduction of the latter, followed by Cope rearrangement generates cycloheptadienylmethanols. These studies demonstrate that (2-alkenyl-3-pentene-1,5-diyl)iron complexes can serve as organometallic scaffolds for the preparation of a wide variety of structural motifs containing up to 5 contiguous stereocenters.     

Research on 2- acyl-3-aminobenzofurans II. Synthesis of heterocyclic systems from 2-acyl-3-aminobenzofuran derivatives

Various condensed heterocyclic systems were obtained from 2-acyl-3-aminobenzofuran derivatives.See [1] for communication I.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1319–1321, October, 1975.     

Synthesis of 3-acyl-1-alkyl-2-alkylseleno-1-cyclobutene using alkyneselenolate

The reaction of lithium alkyneselenolate with alpha,beta-unsaturated ketone and then alkyl or acyl halide afforded 3-acyl-1-alkyl-2-alkylseleno-1-cyclobutene. The structure of the cyclobutene was elucidated by IR, MS, (1)H, (13)C, and (77)Se NMR, COSY, HMQC, and HMBC data and X-ray analysis.     

Bromination of 3-acyl-2-aminoindoles

Unlike 3-acylindoles, 3-acyl-2-aminoindoles display high selectivity on being electrophilically attacked in the benzene ring, and are substituted at the 6-position. At the same time, an unco-subsitution of the acyl group takes place (to the greatest extent — the formyl group). Direct bromination of 3-acyl- and 3-cyano-2-aminoindoles provides the 6-bromo- and 6,4-dibromo-2-aminoindoles and their derivatives.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 486–490, April, 1990.     

Chemistry of Diazopolycarbonyl Compounds: IX. Synthesis of 6-Aryl-3-acyl-4-hydroxypyridazines by Heterocyclization of 1,5-Disubstituted 2-Diazo-1,3,5-pentanetriones

5-Aryl-2-diazo-1,3,5-pentanetriones undergo intramolecular cyclization by the action of triphenylphosphine to give triphenylphosphine oxide and substituted 6-aryl-3-acyl-4-hydroxypyridazines.     

Heterocyclic variants of the 1,5-benzodiazepine system. VI. Derivatives of 2-methylthio-4-(p-r-phenyl)-3H-1,5-benzodiazepines

Ethyl 3-[3H-1,5-benzodiazepin-2-yl]carbazates II were prepared in moderate yields from the title compounds and ethyl carbazate. The compounds II were easily transformed into 1H-s-triazolo[4,3-a][1,5]benzodiazepin-1-ones III via a one-step procedure. Reaction of triazolo-1,5-benzodiazepinones III with sodium hydride in methyl iodide gave a mixture of products from which were isolated two compounds IV and V . The structure of all products was confirmed by ir, ¹H nmr and mass spectrometry.     

Research on 2-acyl-3-aminobenzofurans

It is demonstrated that, depending on the position of the acetyl substituent in the furan ring of benzofuran, the Schmidt rearrangement leads to benzofuran-2-carboxylic acid methylamide or to 3-acetamidobenzofuran derivatives.See [1] for communication II.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1040–1042, August, 1977.