Investigation of reactions of the organozinc reagents prepared from zinc and dialkyl dibromomalonates with the derivatives of 2-arylmethyleneindan-1,3-dione and 5-arylmethylene-2,2-dimethyl-1,3-dioxane-4,6-dione

Organozinc compounds prepared from dialkyl dibromomalonates and zinc react with 2-arylmethyl-eneindan-4,6-diones, 5-arylmethylene-2,2-dimethyl-1,3-dioxane-4,6-diones, as well as with 2-[4-(1,3-dioxoindan-2-ylidenemethyl)phenyl]methyleneindan-1,3-dione and 5-[4-(2,2-dimethyl-4,6-dioxo-1,3-dioxane-2-ylidenemethyl)phenyl]methylene-2,2-dimethyl-1,3-dioxane-4,6-diones to form dialkyl 3-aryl-1′3′-dioxaspiro(cyclopropane-2,2′-indan)-1,1-dicarboxylates, dimethyl 3-aryl-6,6-dimethyl-5,7-dioxa-4,8-dioxaspiro[2,5]octan-2,2-dicarboxylates, dialkyl 2-{4-[3,3-bis (alkoxycarbonyl)-1′,3′-dioxaspiro(cyclopropane-2,2′-indan)-1-yl]phenyl}-1′,3′-dioxaspiro[cyclopropane-2,2′-indan]-1,1-dicarboxylates, and dialkyl 2-{4-[2,2-bis(alkoxycarbonyl)-6,6′-dimethyl-4,8-dioxo-5,7-dioxaspiro[2,5]oct-1-yl]phenyl}-6,6-dimethyl-4,8-dioxo-5,7-dioxaspiro[2,5]octan-1,1-dicarboxylate respectively.     

Three-component condensation of Meldrum’s acid with 2-naphthylamine and esters derived from vanillin

Three-component condensation of Meldrum’s acid (2,2-dimethyl-1,3-dioxane-4,6-dione) with 2-naphthylamine and esters derived from vanillin involves intermediate formation of N-arylmethylidene-2-naphthylamines which are cleaved with Meldrum’s acid to give 5-arylmethylidene-2,2-dimethyl-1,3-dioxane-4,6-diones and arylmethylideneketenes. Reaction of the latter with 2-naphthylamine leads to formation of 2-methoxy-4-(3-oxo-1,2,3,4-tetrahydrobenzo[f]quinolin-1-yl)phenyl carboxylates.     

Heterocyclizations of 5-methylpyrazol-3-amine with unsaturated arylaliphatic carboxylic acid derivatives

Cyclocondensation of 5-methylpyrazol-3-amine with methyl cinnamate and arylmethylidenemalonic acids in DMF and methanol leads to the formation of 7-aryl-2-methyl-6,7-dihydropyrazolo[1,5-a]-pyrimidin-5(4H)-ones. Arylmethylidenemalonic acids react with the title amine at a ratio of 1:2 in nitrobenzene to give 4-aryl-3,5-dimethyl-1,7-dihydrodipyrazolo[3,4-b:4′,3′-e]pyridines. Heterocyclizations of 5-methylpyrazol-3-amine with 5-arylmethylidene-2,2-dimethyl-1,3-dioxane-4,6-diones or their precursors, para-substituted benzaldehydes and 2,2-dimethyl-1,3-dioxane-4,6-dione (Meldrum’s acid) in all solvents (methanol, DMF, and nitrobenzene) give the corresponding 4-aryl-3-methyl-2,4,5,7-tetrahydropyrazolo[3,4-b]pyridin-6-ones. The structure of 3-methyl-4-(4-nitrophenyl)-2,4,5,7-tetrahydropyrazolo[3,4-b]pyridin-6-one was proved by X-ray analysis.     

Asymmetric Catalysis by Vitamin B12: The isomerization of achiral cyclopropanes to optically active olefins

Achiral spiroactivated cyclopropanes are isomerized to optically active (R)-(cycloalk-2-enyl)-Meldrum's acids ( = (R)-5-(cycloalk-2-enyl)-2,2-dimethyl-1,3-dioxane-4,6-diones) in high yield and ee's up to 86% by catalytic amounts of cob(I)alamin in polar protic solvents.     

2,2-Dimethyl-5-(5-R-furfurylidene)-1,3-dioxane-4,6-diones. 3. Selective hydrogenation of the exocyclic double bond and three-dimensional structures of the reaction products

The reaction of 2,2-dimethyl-5-(5-R-furfurylidene)-1,3-dioxane-4,6-diones with sodium borohydride in alcohol leads exclusively to products of hydrogenation of the exocyclic double bond. The three-dimensional structure of one of them — 2,2-dimethyl-5-(5-methyl-furfuryl)-1,3-dioxane-4,6-dioxane — was investigated by x-ray diffraction analysis (XDA).See [1] for Communication 2.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1201–1207, September, 1989.     

5-[(3-吲哚基)-甲基]-2,2-二甲基-1,3-二噁烷-4,6-二酮衍生物的高效合成

在分子碘作用下,以吲哚、醛和2,2-二甲基-1,3-二噁烷-4,6-二酮为原料,通过三组分缩合反应合成了10种5-[(3-吲哚基)-甲基]-2,2-二甲基-1,3-二噁烷-4,6-二酮衍生物。 当催化剂的用量为5%(摩尔分数)时,30 ℃反应60~90 min,收率为71.4%~97.3%。 此外,还探讨了分子碘的催化机理。     

Synthesis and keto-enol tautomerism of 6-alkyl-1-alkoxypyridine-2,4-diones

Reactions of 2,2-dimethyl-5-(3-oxoalkanoyl)-1,3-dioxane-4,6-diones with alkoxyamines proceed regioselectively at the β′-keto group of the side acyl chain affording the corresponding tricarbonyl imines whose boiling in toluene leads to the formation of products of intramolecular cyclization, N-alkoxy-2,4-dioxopyridine-3-carboxylic acids. The decarboxylition of the obtained pyridine-3-carboxylic acids in mesitylene at 160–165°C gives in the preparative yield N-alkoxypyridine-2,4-diones. Proceeding from the IR and NMR spectra the problems of the keto-enol and imine-enamine tautomerism were discussed for the series of 5-acyl derivatives of the Meldrum acid and the obtained N-alkoxypyridine-2,4-diones.     

Synthesis and structure of 1,4-diaryl-7,7-dimethyl-1,2,3,4,5,6,7,8-octahydroquinoline-2,5-diones

Condensation of 5-arylidene-2,2-dimefhyl-1,3-dioxane-4,6-diones with 5,5-dimethyl-3-arylamino-2-cyclohexanones yields 1,4-diaryl-7,7-dimethyl-1,2,3,4,5,6,7,8-octahydroquinoline-2,5-diones. The compounds have been characterized from their IR, UV, and PMR spectra. It has been established that the N-phenyl ring, which projects from the plane of the octahydroquinolinedione ring, has a shielding effect on the magnetic field of the protons at the 7- and 8-positions of the ring in the molecules of the compounds synthesized.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1227–1232, September, 1993.     

Enyne Meldrum´s acid derivatives: synthesis and Michael reactions with amines and thiols

Russian Chemical Bulletin - The Knoevenagel condensation of arylpropynals with Meldrum´s acid in the presence of Et3N affords 5-(3-arylprop-2-yn-1-ylidene)-2,2-dimethyl-1,3-dioxane-4,6-diones...     

Discovery and preliminary SAR of 5-arylidene-2,2-dimethyl-1,3-dioxane- 4,6-diones as platelet aggregation inhibitors

We herein document the discovery of 5-arylidene-2,2-dimethyl-1,3-dioxane-4,6-diones as a novel family of platelet aggregation inhibitors. The preliminary optimization study enabled us to establish the most salient features of the structure-activity relationships in this series as well as to identify novel derivatives that are upto 60 times more potent than the hit structure 1 and slightly superior to the reference drug Milrinone.     

Reactions of Bisazomethines of the Naphtalene Series with 1,3-Diketones

Bisazomethines prepared from aromatic dialdehydes and 2-naphthylamine were for the first time reacted with the following diketones: 1,3-cyclohexanedione, 5,5-dimethyl-1,3-cyclohexanedione, 5-phenyl-1,3-cyclohexanedione, indandione, and 2,2-dimethyl-1,3-dioxane-4,6-dione was studied. The reactions with 1,3-diketones of the cyclohexane series yield benzophenanthridine derivatives. The reactions with indandione, depending on conditions, give either bisarylideneindandiones or bisdihydrobenzo[f]indenoquinoline. As evidenced by the ^13C NMR and IR spectra, in the case of biphenyl-4,4'-dicarbaldehyde bis[N-(2-naphthyl)imine] and 2,2-dimethyl-1,3-dioxane-4,6-dione, 4,4'-bis(3-oxo-1,2,3,4-tetrahydrobenzo[f]quinolin-1-yl)biphenyl is formed.     

Reactions of bromine-containing organozinc compounds derived from α,α-dibromo ketones with 2-arylmethylideneindan-1,3-diones and 5-arylmethylidene-2,2-dimethyl-1,3-dioxane-4,6-diones

Bromine-containing organozinc compounds generated from 1,1-dibromo-3,3-dimethylbutan-2-one reacted with 2-arylmethylideneindan-1,3-diones and 5-arylmethylidene-2,2-dimethyl-1,3-dioxane-4,6-diones to give 3-aryl-2-(2,2-dimethylpropanoyl)spiro[cyclopropane-1,2′-indan]-1′,3′-diones and 1-aryl-6,6-dimethyl-2-(2,2-dimethylpropanoyl)-5,7-dioxaspiro[2.5]octan-4,8-diones, respectively. Reactions of 2-arylmethylideneindan-1,3-diones with bromine-containing zinc enolates derived from 1-aryl-2,2-dibromopropan-1-ones and 2,2-dibromo-1,2,3,4-tetrahydronaphthalen-1-one resulted in the formation of 2-aroyl-3-aryl-2-methylspiro-[cyclopropane-1,2′-indan]-1′,3′-diones and 2,3: 8,9-dibenzo-12-phenyldispiro[4.0.5.1]dodecane-1,4,7-trione, respectively.     

Reaction Between 5-Isopropylidene-2,2-dimethyl-1,3-dioxane-4,6-dione and <Emphasis Type="Italic">tert</Emphasis>-Butyl Isocyanide in the Presence of Primary or Secondary Amines

Summary. 5-Isopropylidene-2,2-dimethyl-1,3-dioxane-4,6-dione (the condensation product of Meldrums acid and acetone) reacts smoothly with tert-butyl isocyanide in the presence of primary or secondary amines to produce N-tert-butyl-2,2-dimethylbutyramide derivatives and/or 1-tert-butyl-4,4-dimethyl-2,5-dioxopyrrolidine-3-carboxamides in good yields.     

1,3-Dipolar cycloaddition of phthalazinium ylides to 5-arylidene-2-spirocyclohexane-1,3-dioxane-4,6-diones

Tetrahydrospiropyrrolo[2,1-a]phthalazines were synthesized by the reaction of 5-arylidene-2-spirocyclohexane-1,3-dioxane-4,6-diones with phthalazinium ylides. One of the reaction products, viz., 3-ethoxycarbonyl-2-(4-methoxyphenyl)-2′,2′-pentamethylene-1,2,3,10b-tetrahydrospiro[pyrrolo[2,1-a]phthalazine-1,5′-[1,3]dioxane]-4′,6′-dione, was studied by X-ray diffraction. The spectroscopic characteristics of the reaction products are discussed. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 2362–2365, October, 2005.     

无外加催化剂条件下芳香醛与活性亚甲基化合物的缩合反应和迈克尔加成反应

在DMF溶剂中，不外加催化剂使芳香醛(1)与2,2-二甲基-1,3-二氧六环-4,6-二酮(2)发生缩合反应生成2,2-二甲基-5-芳亚甲基-1,3-二氧六环-4,6-二酮(3a～f)。在同样条件下，芳香醛与5,5-二甲基-1,3-环己二酮(4)则发生缩合和迈克尔加成反应生成2,2'-芳亚甲基双(3-羟基5,5-二甲基-2-环己烯-1-酮)(5a～h)。用单晶X-射线分析法确定了产物5b的晶体结构。     

Diels–Alder Reactions with Cyclic Sulfones: VII. Synthesis of 1-Benzothiophene 1,1-Dioxide Derivatives

5-Arylmethylene-2,2-dimethyl-1,3-dioxane-4,6-diones reacted with 5-isopropenyl-2,3-dihydrothio-phene 1,1-dioxide to give the corresponding ortho-addition products, 5-aryl-2',2',7-trimethyl-3,3a,5,6-tetra-hydro-2H-spiro[1-benzothiophene-4,5'-[1,3]dioxane]-4',6'-dione 1,1-dioxides. Their aminolysis resulted in opening of the 1,3-dioxane ring and formation of 4-carbamoyl-7-methyl-2,3,3a,4,5,6-hexahydro-1-benzo-thiophene-4-carboxylic acid 1,1-dioxide whose structure was determined by X-ray analysis. Reactions of the spiro adducts with amines and hydrazine hydrate afforded the corresponding mono- or dicarboxylic acid monoamides (hydrazide).     

Synthesis of 1,6-disubstituted 2,4-pyridinediones from 5-acetoacetyl-2,2-dimethyl-1,3-dioxane-4,6-dione

5-Acetoacetyl-2,2-dimethyl-1,3-dioxane-4,6-dione reacts with aliphatic amines and p-methoxy-aniline to afford the corresponding 5-[3-alkyl(or aryl)amino-2-butenoyl] derivatives. Heating of the latter in boiling toluene gives 86–90% of N-substituted 6-methylpyridine-3-carboxylic acids which undergo decarboxylation in diethylene glycol dimethyl ether at 160°C, leading to N-substituted 6-methyl-1,2,3,4-tetrahydro-pyridine-2,4-diones in high yields.Translated from Zhurnal Organicheskoi Khimii, Vol. 40, No. 9, 2004, pp. 1376–1378.Original Russian Text Copyright © 2004 by Rubinov, Zheldakova, Rubinova.     

5-取代丙二酸亚异丙酯的结构研究 II: 5-(α-异丙基)-2,2-二甲基-1,3-二氧杂环乙烷-4,6-二酮的晶体结构及量子化学计算

5-(α-异丙基)-2,2-二甲基-1,3-二氧杂环己烷-4,6-二酮C9H14O4, MT=186.21, 正交晶系, 空间群为P212121, 晶胞参数为: a=5.228(1), b=11.079(4), c=16.955埃.V=892.1(5)埃^3, Dc=1.286g.cm^-^3. Z=4, μ(MoKa)=0.92cm^-^1. 用直接法解出结构, 经最小二乘法修正, 最后的偏离因子R=0.062. 结构 测定表明, 分子内六元环具有扭曲船式结构. 对5-(α-苯乙基)-2,2-二甲基-1,3-二氧杂环己烷-4,6-二酮的CNDO/2计算表明, 最稳定构型是扭曲船式结构, 与X射线晶体分析 结果相一致.     

Efficient Synthesis of Highly Functionalized,S -Alkyl 1-Alkyl-4,4-dimethyl-2,5-dioxo-pyrrolidine-3-carbothioates

5-Isopropylidene-2,2-dimethyl-1,3-dioxane-4,6-dione (the condensation product of Meldrum's acid and acetone) reacts with alkyl isocyanides in the presence of this to produce S -alkyl 1-alkyl-4,4-dimethyl-2,5-dioxo-pyridine-3-carbothioates in good yield.     

Reaction of N,N'-Di(methoxycarbonyl)-p-benzoquinonediimine with Meldrum's Acid and its Analogs

Reactions of 2,2-dimethyl-4,6-dioxo-1,3-dioxane (Meldrum's acid), 2,2-tetramethylene-4,6-dioxo-1,3-dioxane and 2,2-pentamethylene-4,6-dioxo-1,3-dioxane in the presence of MeONa gave rise instead of expectable products of Michael 1,4-addition the corresponding N,N'-di(methoxycarbonyl)-p-benzoquinonediimines substituted in the ring.