A Novel Synthesis of Dimethyl Malonate by Carbonylation of Methyl Chloroacetate Catalyzed by Cobalt Complex

Dimethyl malonate (DMM) is an important organic synthesis intermediate. Traditional synthetic method by reaction of mono-chloroacetic acid with sodium cyanide1 is poisonous and complicated. Therefore, an interest in green synthesis routes of DMM has risen greatly. The several processes for preparing DMM by carbonylation of methyl chloroacetate catalyzed by Co2(CO)8 have been reported2~5. However, Co2(CO)8 is unstable and must be prepared under high pressure (12 Mpa). Moreover, the yield…     

3,5—二甲氧基苯乙醛和丙二酸单乙酯的Knoevenagel缩合

从３,５－二甲基苯乙醛和丙二酸单乙酯的Ｋｎｏｅｖｅｎａｇｅｌ缩合反应得到２个产物,其一经证实是重排生成的４－（３,５－二甲氧苯基）－３－丁烯酸乙酯,另一个是２＇,４＇,２″,４″－四甲氧基－２,３：６,７－二苯并－９－氧杂双环［３．３．１］壬－２,６－二烯。经元素分析、ＩＲ、ＮＭＲ、ＭＳ、和Ｘ射线衍射证实前者不发生可逆重排为其２－烯酸酯异构体的反应。     

Reactions of 3-(4-Aryl-2-thiazolyl)- and 3-(2-Benzothiazolyl)-2-iminocoumarins with N-Nucleophiles

The reaction of 3-(4-aryl-2-thiazolyl)- and 3-(2-benzothiazolyl)-2-iminocoumarins with N-nucleophiles was studied. This reaction gives 2-N-substituted 3-(4-aryl-2-thiazolyl)- and 3-(2-benzothiazolyl)iminocourmarins. N-Nucleophiles such as arylamines, heterocyclic amines, and hydrazine derivatives undergo this reaction.     

吲哚与亚烷基丙二酸二甲脂Michael加成反应机理的从头算研究

在HF/6-31G(d)水平下, 对吲哚(A)与亚烷基丙二酸二甲脂(B)的Michael加成反应的机理进行了从头算理论研究. 计算结果表明, 该反应的机理为: A＋B→分子复合物→TS1→IM→TS2→产物. 其中第一阶段由复合物经过渡态TS1生成中间体IM, 是C—C键的形成阶段, 该阶段的活化能垒较后一阶段要大, 是该反应的决速步骤; 第二阶段由IM经过渡态TS2生成产物, 完成H迁移和C—H键的形成. 反应过程中, 底物分子中离域化的π键电子的相互作用, 促进了 C—C新键的形成, 同时吲哚的共轭体系遭到部分破坏, 而体系经H迁移使新的C—H键形成后, 吲哚环的共轭体系又得到了恢复. 在MP2/6-311＋G(d,p)水平下, 分别考虑乙醇和1,2-二氯乙烷的溶剂化效应, 单点能计算结果显示, 质子化溶剂对反应的影响较大, 不仅降低了反应的能垒, 且溶剂质子有可能参与了H迁移和C—H键的形成过程, 这一结论与实验结果一致.     

邻硝基酚醚上的异常取代反应

以2-(2-硝基苯氧基)-1-溴乙烷或3-(2-硝基苯氧基)-1-溴丙烷为原料分别在氢化钠作用下与N-Boc-4-羟基哌啶反应,得到了与预期结构不同的产物.该产物的结构经1H NMR,13C NMR,LC-MS分析表明,其并非为原料2-(2-硝基苯氧基)-1-溴乙烷与N-Boc-4-羟基哌啶发生Williamson反应生成预期的混合醚,而是芳环上的烷氧基被取代的异常产物.根据这个实验结果,推测上述反应的可能机理是发生了芳环上的亲核取代反应.     

4-(4-羟基丁基－2－炔氧基)－3-（苯磺酰基）－1，2，5－噁二唑－2－氧化物与牛血清白蛋白结合作用的光谱法研究

The interaction between 4-(4-hydroxybut-2-ynyloxy)-3-(phenylsulfonyl)-1,2,5-oxadiazole-2-oxide(FB)andbovine serum albumin(BSA)was studied by spectroscopic methods including fluorescence and UV-Vis absorptionspectroscopy.The quenching mechanism of fluorescence of BSA by FB was considered to be a dynamic quenchingprocedure.The number of binding sites n and apparent binding constant K were measured by fluorescence quench-ing method.The results indicate that there is FB molecular binding with BSA,and forming 1∶1 complex.Thethermodynamic parameters such as ΔH,ΔG and ΔS,etc.,were calculated.The results indicate that the binding reac-tion is mainly entropy-driven and hydrophobic forces play major role in the binding reaction.The distance r be-tween donor(BSA)and acceptor(FB)was obtained according to Frster theory of non-radioactive energy transfer.     

Reaction of furfurylidene acetone with Grignard reagents

The interaction of furfurylidene acetone with methylmagnesium iodide and ethylmagnesium halides has been studied. In the first case 2-methyl-4-(2-furyl)-3-buten-2-ol is formed as the product of 1,2-addition (yield 73 %). In the second case 4-(2-furyl)-2-hexanone (42 %) is the result of 1,4-addition, whereas 3-methyl-5-(2-furyl)-3-heptanol (45 %) is formed by consecutive 1,2- and 1,4-addition. In all cases the products of 1,3-addition were found.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 921–923, May, 1993.     

分子筛超强酸SO_4~(2-)/TiO_2/USY催化合成胡萝卜酸乙酯的研究

以USY分子筛为载体,采用共沉淀-浸渍法制备分子筛超强酸SO42-/Ti O2/USY,用其催化丙二酸、无水乙醇合成胡萝卜酸乙酯。考察了不同反应时间、带水剂种类、带水剂用量、醇酸比、催化剂用量、催化剂重复使用性等因素对反应酯化率的影响。结果表明:在丙二酸用量为0.1mol,醇酸摩尔比为3.1:1,催化剂用量为1.0g,反应时间为3h,带水剂环已烷用量为5m L时,酯化率达到92.13%,催化剂重复使用5次以后仍然有很高的活性。说明SO42-/Ti O2/USY对该反应具有很强且极稳定的催化活性。     

Reactions of 2-methylindole with morpholinals of substituted salicylaldehydes

Fusion of 2-methylindole with morphinals of substituted salicylaldehydes (in a ratio of 1 : 1) afforded 3-[(2-hydroxyaryl)morpholinomethyl]-2-methylindoles as normal products of the Mannich reaction. In some cases, the reactions with an excess of 2-methylindole resulted in unusual condensation accompanied by the replacement of the OH group by the morpholino group to form bis(2-methylindol-3-yl)(2-morpholinoaryl)methanes.     

2-Polyfluoroalkylchromones. 7. Reactions of 6-substituted 2-tetra- and 2-pentafluoroethylchromones with 2-aminoethanol

The reactions of 2-aminoethanol with 6-methyl-2-tetra- and 6-methyl-2-pentafluoroethylchromones involve the carbonyl group to give imines; the reactions with 6-nitro-2-tetra- and 6-nitro-2-pentafluoroethylchromones involve the C(2) atom, resulting in the pyrone ring opening. This also occurs in the reactions of 2-(1,1,2,2-tetrafluoroethyl)chromone with ammonia and benzylamine.     

Reactions with pyrrolidine-2,4-diones,II: New approaches to the synthesis of substituted 5,6-dihydropyrrolo[3,4-d][1,2,3]triazol-4(2H,4H)ones

Summary Approaches leading to 5,6-dihydro-5,6-diphenyl-2-substituted-pyrrolo[3,4-d][1,2,3]-triazol-4(2H,4H)-ones (10) are described. The first approach consists of cyclodehydrating 3(or 4)-hydroxyimino-1,5-diphenyl-4(or 3)-(4-substituted phenylhydrazono)pyrrolidin-2-ones (4,7) with boiling acetic anhydride. The second approach involves cyclization of 3(or 4)-acetoxyimino-1,5-diphenyl-4(or 3)-(4-substituted phenylhydrazono)pyrrolidin-2-ones (8,9) with elimination of acetic acid upon treatment with sodium hydroxide.Part of the work has been presented at the 8^th International Congress of Heterocyclic Chemistry (August 1981), Graz, Austria     

Al2（SO4）3／SiO2催化甲醇脱水合成二甲醚

采用浸渍法制备了不同负载量的Al2（SO4）3／SiO2催化剂．使用BET、XRD、FT—IR、异丙醇探针反应、NH3吸附量热和NH3吸附红外等手段对催化剂进行了表征,并测试了其在甲醇脱水合成二甲醚反应中的活性．BET、XRD和FT-IR结果表明,载体SiO2的表面积较高,随着Al2（SO4）3负载量的增加,样品的表面积逐渐降低,当Al2（SO4）3负载量高于20％时,样品表面开始出现晶相Al2（SO4）3．NH3吸附量热和NH3吸附红外结果表明,载体SiO2的酸性很弱,负载了Al2（SO4）3后,样品酸性大大增强,且酸性随着Al2（SO4）3负载量的增加先增强后减弱．样品表面同时存在B酸中心和L酸中心,但以B酸中心为主．Al2（SO4）3负载量为3％的样品的表面酸性最强,因而在甲醇脱水反应中表现出最高的反应活性,533K,甲醇转化率为83．5％,二甲醚选择性100％．     

Sydnone Compounds XXX. The Syntheses and Reactions of 3-Aryl-4-Cyanosydnones and 3-Aryl-4-Formylsydnone Oximes

In the presence of pyridine, 3-aryl-4-formylsydnone (II) reacts with hydroxyl-amine hydrochloride to produce 3-aryl-4-formylsydnone oxime (III). This reaction was performed in ethanol solution with reflux or at room temperature; the latter procedure gave an excellent yield (74-98%) and high purity. (III) reacts in acetic anhydride at room temperature to give 3-aryl-4-formylsydnone oxime O-acetate (IV). A convenient method for the synthesis of 3-aryl-4-cyanosydnone (V) is to dehydrate (III) with acetic anhydride at reflux. When (IV) was refluxed with acetic anhydride, (V) was similarly obtained. Another convenient method to prepare (V) from (III), dehydration with thionyl chloride at room temperature, was also investigated.     

Synthesis of 4-Hydroxy- and 4-Amino-2-Methyl-3-(2-Methylindol-3-Yl)methylquinolines and Their 6- and 8-Substituted Derivatives

A method has been developed for the synthesis of substituted 4-hydroxy- and 4-amino-2-methyl-3-(2-methylindol-3-yl)methylquinolines by treating the corresponding 4-hydroxy(chloro)-2-methyl-3-(3-oxobutyl)quinolines with phenylhydrazine hydrochloride. It was found that nucleophilic substitution occurred in the case of the 4-chloroquinolines together with subsequent rearrangement to give the 4-amino derivatives. The thiosemicarbazones of the corresponding 4-hydroxy-2-methyl-3-(3-oxobutyl)quinolines were also obtained.__________Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 554–557, April, 2005.     

Reactions of terminal acylacetylenes with thiocarbohydrazones

The reactions of terminal acylacetylenes with thiocarbohydrazones give 2-(2-acyl-vinyl)thiocarbohydrazones or 2,2-bis(2-acylvinyl)thiocarbohydrazones depending on the reagent ratio. Benzoylacetylene reacts with thiocarbohydrazone ofp-dimethylaminobenzaldehyde to formS-[2-(p-dimethylaminobenzoyl)vinyl]isothiocarbodihydrazone. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 2083–2085, October, 1998.     

Reaction of Isatoic Anhydride,Amine, and N,N′-Dialkyl Carbodiimides Under Solvent-Free Conditions: New and Efficient Synthesis of 3-Alkyl-2-(alkylamino)quinazolin-4(3H)-ones

Heating a mixture of isatoic anhydride, amines, and N,N′-dialkyl carbodiimides under solvent-free conditions provided novel 3-alkyl-2-(alkylamino)quinazolin-4(3H)-one derivatives for the first time. The products were obtained in moderate to good yields without formation of any by-products.

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Synthesis and Reactions of a Stable Precursor to Dienes Containing Both Silicon and Sulfur Substituents

3-(Phenylthio)-4-(trimethylsilyl)-3-sulfolene (2) was readily prepared by chlorosulphenylation-dehydrochlorination of 3-(trimethylsilyl)-3-sulfolene (4b) . Treatment of 2 with n-butyllithium at ?105 °C followed by an alkylating agent gave only C5 alkylation products 6 demonstrating the stronger carbanion stabilizing ability of phenylthio group than that of trimethylsilyl group. 2-(Phenylthio)-3(trimethylsilyl)-1,3-butadiene (3a) was readily prepared by thermal extrusion of sulfur dioxide from 2 . Selective oxidation of 3a with MCPBA gave the sulfinyl (3b) and sulfonyl (3c) derivatives. The Diels-Alder reactions of 3a-c were studied, and the regiocontrolling power of the substituents follows the order PhS >PhSO ～ PhSO₂ >Me₃Si.     

The Synthesis and Reactions of N-Hydroxy-3-Arylsydnone-4-Carboxamide Oximes

N-Hydroxy-3-arylsydnone-4-carboxamide oximes (7) were prepared from the corresponding 3-arylsydnone-4-carbohydroximic acid chlorides (6) and hydroxylamine in high yield. The chemical reactivity of compound (2) is somewhat different from 3-arylsydnone-4-carboxamide oximes (2) in that the former compounds reacted with both aromatic and aliphatic aldehydes in the presence of acid catalyst to give 3-aryl-4-(5-aryl-1,2,4-oxadiazol-3-yl)sydnones (5) and 3-aryl-4-(5-alkyl-1,2,4-oxadiazol-3-yl)sydnones (3).