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.     

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.     

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。     

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.     

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.     

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.     

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.     

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。     

Preparative synthesis of 2,2-dimethyl-5-(trifluoroacetyl)-1,3-dioxane-4,6-dione (2-trifluoroacetyl Meldrum's acid) and 2,2-dimethyl-6-(trifluoromethyl)-4H-1,3-dioxin-4-one and their synthetic usefulness as (trifluoroacetyl)ketene precursors

A simple and reliable method for the preparation of 2,2-dimethyl-5-(trifluoroacetyl)-1,3-dioxane-4,6-dione and 2,2-dimethyl-6-(trifluoromethyl)-4H-1,3-dioxin-4-one on a multigram scale was developed. These (trifluoroacetyl)ketene precursors were used in the hetero-Diels-Alder reaction with dialkylcyanamides and 1-ethoxyprop-1-yne, as well as in some reactions with nucleophiles.     

New thiourea organocatalysts and their application for the synthesis of 5-(1H-indol-3-yl)methyl-2,2-dimethyl-1,3-dioxane-4,6-diones a source of chiral 3-indoylmethyl ketenes

The stereoselective properties of modified thiourea organocatalysts were tested in the Friedel–Crafts alkylation of indole with 5-arylidene-2,2-dimethyl-1,3-dioxane-4,6-diones, which produces chiral 5-((1H-indol-3-yl)(aryl)methyl)-2,2-dimethyl-1,3-dioxane-4,6-diones. Based on a tentative reaction mechanism for ((S)-N-benzyl-2-(3-(3,5-bis(trifluoromethyl)phenyl)thioureido)-N,3,3-trimethylbutanamide organocatalysts, modifications were applied in four selected regions. Systematic structure-stereoselectivity relationship study allowed designing the best efficient organocatalyst for the investigated Friedel–Crafts alkylation of indole with 5-arylidene-2,2-dimethyl-1,3-dioxane-4,6-diones.     

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.     

One-Step Formation of N-Alkenyl-malonamides and N-Alkenyl-thiomalonamides from Carbamoyl Meldrum's Acids

A one-pot synthesis for the preparation of N-alkenyl-malonamides and N-alkenyl-thiomalonamides was developed. 5-[Hydroxy/mercapto(aryl/alkylamino)methylene]-2,2-dimethyl-1,3-dioxane-4,6-dione act as a source of ketenes that react with the tautomeric form of alkyl-(2-phenyl-propylidene)-amines. A possible [2 + 2] or [4 + 2] cycloaddition product of ketene to imines was not observed.     

Cyclotrimerization of alkynes catalyzed by the naphthalene ruthenium complex [CpRu(C10H8)]+

The naphthalene ruthenium complex [CpRu(C₁₀H₈)]⁺ (in the presence of Cl^? ions) catalyzes the cyclotrimerization of 2,2-dimethyl-5,5-dipropargyl-1,3-dioxane-4,6-dione with alkynes (acetylene, hex-1-yne, hex-3-yne, oct-1-yne, phenylacetylene, trimetylsilylacetylene, octa-1,7-diyne, pent-1-yn-5-ol, methyl propargyl ether, and propargyl acetate) giving tricyclic aromatic compounds in 55–85% yields.     

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.     

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.     

无溶剂硼酸高效合成螺杂双环衍生物

在硼酸催化下,芳香醛、尿素和2,2-二甲基-1,3-二噁烷-4,6-二酮在无溶剂条件下合成了8种螺杂双环衍生物。 当催化剂的用量为10%(摩尔分数)时,80 ℃反应2.0~4.0 h,收率为74%~93%。 此外,还探讨了硼酸可能的催化机理。 该方法具有条件温和,后处理工艺简单及收率高的优点。     

A novel solvolytic rearrangement of 2,2-dimethyl-5-(1-Bromomethylethylidene)-1, 3-dioxane-4,6-dione

Treatment of the title compound under basic aqueous conditions leads to 2,2-dimethyl-5-(2-ketopropyl)-1,3-dioxane-4,6-dione; the structure and mechanism of formation of this compound is described.     

新型树形化合物1,3,5-三-[7-(7-甲基-2,2-二-(2,2-二羟甲基-3-羟基丙氧基羰基)-6,8-二氧杂螺[3.5]-壬基)]苯的合成

以丙酮和甲酸乙酯为原料, 在醇钠的作用下合成了1,3,5-三乙酰基苯(1). 1与二溴新戊二醇在酸的作用下发生缩酮化反应, 制成1,3,5-三-(1-甲基-2,6-二氧杂-4,4-二溴甲基环己基)苯(2). 2与5,5-二甲基-4,6-二氧杂-1,3-环己二酮在乙醇钠的作用下合成了1,3,5-三-[7-(7-甲基-2,2-二-乙氧羰基-6,8-二氧杂螺[3.5]-壬基)]苯(3). 将3在氯仿中与季戊四醇进行酯交换反应得到产物1,3,5-三-[7-(7-甲基-2,2-二-(2,2-二羟甲基-3-羟基丙氧基羰基)-6,8-二氧杂螺[3.5]-壬基)]苯(4). 收率为47.7%. 标题化合物及中间产物使用IR, ¹H NMR和MS或元素分析进行了表征.     

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).     

The reduction and hydrolysis of some 7,7-diethylpyrazolo[1,2-a]-pyridazine-6,8(7H)dione derivatives

The chemistry of several of the Diels-Alder adducts formed by the reaction of 4,4-diethylpyrazoline-3,5-dione ( 1 ) with conjugated dienes was studied with respect to reduction (hydride and catalytic) and reaction with base. Reaction of the 2,3-dimethyl-1,3-butadiene adduct with lithium aluminum hydride followed by hydrogenation gave 1,3,5,6,7,8-hexahydro-cis-endo-6,7-dimethyl-2,2-diethylpyrazolo[1,2-a]pyridazine ( 11 ). Attempted conversion of this compound to 3,3-diethyl-cis-7,8-dimethyl-1,5-diazacyclononane ( 12 ) gave instead a compound which has been tentatively identified as N-(2,3-dimethyl-4-aminobutyl)-2-ethyl-2-methylbutanaldimine ( 14 ). Lithium aluminum hydride reduction of 4,4-diethylpyrazolidine-3,5-dione ( 22 ) or the adducts formed from 1 and cyclopentadiene or 1,3-cyclohexadiene gave good yields of 4,4-diethylpyrazolidine ( 21 ). This later reduction gave a new and efficient synthetic route to the pyrazolidine ring system. Lithium aluminum hydride reduction of 5,6,7,8-tetrahydro-5,8-ethano-2,2-diethylpyrazolo[1,2-a]pyridazine-1,3(2H)dione ( 26 ) followed by hydrogenolysis led to a high yield of 4,4-diethyl-2,6-diazabicyclo[5.2.2]undecane ( 28 ) which is the first reported example of this ring system. Reaction of several of the adducts with ethanolic potassium hydroxide resulted in the opening of the five-membered ring.