A novel efficient synthetic method for 2,2',3,3'-biphenyltetracarboxylic dianhydride

A novel approach to the synthesis of 2,2',3,3'-biphenyltetracarboxylic dianhydride is described. The target compound was prepared by a nickel-catalyzed coupling reaction of dimethy 3-chlorophthalate (3-DMCP) for 4 h at 70-80 C, followed by subsequent hydrolysis of tetra-ester in acid solution and dehydration of tetra-acid, with overall yield of 68%. The structures of the products were characterized by IR, 1H NMR and 13C NMR respectively.     

A novel efficient synthetic method for 2,2＇,3,3＇-biphenyltetracarboxylic dianhydride

A novel approach to the synthesis of 2,2',3,3'-biphenyltetracarboxylic dianhydride is described. The target compound was prepared by a nickel-catalyzed coupling reaction of dimethy 3-chlorophthalate (3-DMCP) for 4 h at 70-80℃, followed by subsequent hydrolysis of tetra-ester in acid solution and dehydration of tetra-acid, with overall yield of 68%. The structures of the products were characterized by IR, ¹H NMR and ¹³C NMR respectively.     

无外加催化剂条件下邻取代芳香醛与5,5-二甲基-1,3-环己二酮的反应研究

在DMF溶剂中,不外加催化剂使邻取代芳香醛(1)与5,5-二甲基-1,3-环己三酮(2)发生缩合和加成反应生成3,3,6,6-四甲基-4a-羟基-9-芳基-1,8二氧化-2,3,4,4a,5,6,7,8,9a-十氢化-1H氧杂蒽(3a～3d)。在同样条件下,邻羟基芳香醛与5,5-二甲基-1,3-环己三酮则发生缩合,加成和脱水反应生成3,3-二甲基-9-(5,5-二甲基-3-羟基-2-环己烯-1-酮-2-基)-1-氧代-2,3,4,9-四氢化-1 氧杂蒽(4a～4b)。用单晶X-射线分析法确定了产物3a和4a的晶体结构。     

Reactions of dimethyl acetylenedicarboxylate—X: Reaction with salicylaldehyde,ortho hydroxyacetophenone, 2-hydroxychalcones and 2,2′-dihydroxychalcones

Salicylaldehyde reacts with dimethyl acetylenedicarboxylate in benzene solution to give a mixture of dimethyl o-formylphenoxymaleate, dimethyl o-formylphenoxyfumarate, 2,3-dicarbomethoxychrom - 2 - en - 4 - ol, 2,3 - dicarbomethoxychrom - 3 - en - 2 - ol, dimethyl (2,3 - dicarbomethoxychrom - 2 - en - 4 - yl) - oxalacetate and dimethyl fumarate. 2,3 - Dicarbomethoxychrom - 3 - en - 2 - ol in this reaction is formed from 2,3 - dicarbomethoxychrom - 2 - en - 4 - ol through a benzopyrylium intermediate. The reaction of salicylaldehyde with excess of dimethyl acetylenedicarboxylate, however, gives a mixture of 2,3 - dicarbomethoxychrom - 3 - en - 2 - ol and dimethyl (2,3 - dicarbomethoxychrom - 3 - en) - 2 - oxyfumarate. 2,3 - Dicarbomethoxychrom - 3 - en - 2 - ol itself reacts further with dimethyl acetylenedicarboxylate to give 2,3,12 - tricarbomethoxychrom - 3,4 - eno[2,3 - b] pyrone. Similarly, the reaction of o-hydroxyacetophenone with dimethyl acetylendicarboxylate gives a mixture of dimethyl o-acetylphenoxymaleate, dimethyl o-acetylphenoxyfumarate, 2,3 - dicarbomethoxy - 4 - methylchrom - 2 - en - 4 - ol and 2,3 - dicarbomethoxy - 4 - methylchrom - 3 - en - 2 - ol. Both 2-hydroxychalcone and 2 - hydroxy - 4′ - methoxychalcone give mixtures of chalcone - 2 - oxymaleate and chalcone - 2 - oxyfumarate. The reaction of 2,2t?-dihydroxychalcone, however, gives 2′-hydroxyflavone, in addition to the expected maleate and fumarate. Similar reactions of 5 - chloro - 2,2′ - dihydroxychalcone and of 3,5 - dibromo - 2,2′ - dihydroxychalcone, on the other hand, give 2,3 - dicarbomethoxy - 4 - (o - hydroxyphenacyl) - 6 - chlorochrom - 2 - ene and 2,3 - dicarbomethoxy - 4 - (o - hydroxyphenacyl) 6,8 - dibromochrom - 2 - ene, respectively, together with the corresponding maleates and fumarates.     

Synthesis and Chemical Behaviour of 4, 5-Dideoxy-4, 5-Epithio-2, 3-DI-0-Methanesulfonyl-L-Xylose Dimethyl Acetal

ABSTRACT

Selective substitution of the primary sulfonate group in 2, 3, 4, 5-tetra-0-methanesulfonyl-D-arabinose dimethyl acetal (1) gives 5-S-acetyl-2, 3, 4-tri-0-methanesulfonyl--5-thio-D-arabinose dimethyl acetal (2) which is further converted into the title compound (3). Reductive desul-furization of 3 afforded deoxy dimethyl acetal derivatives 5 and 6 in a low yield. Unsaturated monosaccharide derivative 7 was obtained as the only reaction product from 3 with triphenylphosphine. Catalytic hydrogenation of 7 gave dideoxy-sugar 6 in a satisfactory yield. Finally, epi-sulfide 3 with acetyl chloride afforded 4-chloro-4-deoxy derivative 4, which can be recycled into the starting 3.     

多取代芳香族化合物的合成 5.卤素-苯硒基取代的丁二烯和丁炔二酸二甲酯的环加成-芳构化串连反应

本文报道用环加成－芳构化串连反应制备多取代芳香族化合物的方法。将１－氯－２－卤－３－苯硒基－１，３－丁二烯（５）与丁炔二酸二甲酯进行Ｄｉｅｌｓ－Ａｌｄｅｒ反应时，能直接生成多取代的芳香族化合物４－苯硒基－５－卤代邻苯二甲酸二甲酯（４）。若用２－卤素－３－苯硒基－１，３－丁二烯（１）与丁炔二酸二甲酯进行Ｄｉｅｌｓ－Ａｌｄｅｒ反应，只得到正常的加成产物４－苯硒基－５－卤素－１，４－环己二烯－１，２－二甲酸二甲酯（３），需再用ＤＤＱ处理，才得到多取代芳香族化合物（４）。     

Aminomercuration-demercuration of dimethyl(chloroalkyl)alkenylsilanes as a route to azasilacycloalkanes

3,3-Dimethyl-1-phenyl-1-aza-3-silacyclopentane and 3,3,5-trimethyl-1-phenyl-1-aza-3-silacyclopentane were obtained by the reaction of dimethyl(chloromethyl)vinylsilane and dimethyl(chloromethyl)allylsilane with aniline in THF in the presence of mercury acetate followed by reduction with sodium borohydride. Aminomercuration-demercuration of dimethyl(3-chloropropyl)vinylsilane and dimethyl(3-chloropropyl)allylsilane results in the corresponding 3-chloropropylphenylaminoalkyl derivatives. Dimethyl(3-chloropropyl)(2-phenylaminopropyl)-silane undergoes cyclization under the same reaction conditions giving 2,4,4-trimethyl-1-phenyl-1-aza-4-silacycloheptane in low yield. Competitive nucleophilic substitution of the chloroalkyl group of initial silanes by aniline affords dimethyl(phenylaminoalkyl)alkenylsilanes.     

Reactions of Zinc Enolates Formed from 1-Aryl-2-bromo-2-phenylethanone or 2-Bromoindanone and Zinc,with Dimethyl 2-(1-Arylmethylene)malonates

Zinc enolates formed from 1-aryl-2-bromo-2-phenylethanones and zinc react with dimethyl 2-(1-arylmethylene)malonates to afford dimethyl 2-(1,3-diaryl-3-oxo-2-phenylpropyl)malonates. The latter react with cyclohexylamine, piperidine, or morpholine to give the corresponding monosubstituted amides. The zinc enolate derived from 2-bromoindanone and zinc reacts with dimethyl 2-(4-bromobenzylidene)malonate, yielding dimethyl 2-[(4-bromophenyl)(1-oxoindan-2-yl)methyl]malonate. The final products largely form as a single diastereomer.     

微波辐射下芳醛与活性亚甲基化合物的反应

芳醛、5，5－二甲基－1，3－环己二酮、丙二酸亚异丙酯经微波辐射发生缩合、加成、环化及消去反应，一步合成了7，7－二甲基－4－芳基－2，5－二氧代－1，2，3，4，5，6，7，8－八氢喹啉和7，7－二甲基－4－芳基－5－氧代－3，4，5，6，7，8－六氢香豆素，反应在3－5min内完成，产率优良。产物的结构经红外及核磁共振等方法确证。     

Methylation of 3-methyl- and 3-phenyl-4-arylhydrazonoisoxazol-5-ones with methyl iodide and dimethyl sulfate

Methylation of 3-methyl-4-arylhydrazonoisoxazol-5-ones with methyl iodide affords both 2,3-dimethyl-4-arylazoisoxazol-5-ones and 3-methyl-4-(N-methylarylhydrazono)isoxazol-5-ones but with dimethyl sulfate only the former products are formed. 3-Phenyl-4-arylhydrazonoisoxazol-5-ones behave in a similar way on methylation with methyl iodide and dimethyl sulfate.     

Methylation and amination of folic acid

The methylation of folic acid (2) with excess methyl iodide resulted in the formation of dimethyl 1,3-dimethylfolate ( 4 ), whereas, methylation of dimethyl folate ( 3 ) with an equimolar amount of methyl iodide gave mainly dimethyl 3-methylfolate ( 6 ). Both 4 and 6 underwent the Dimroth rearrangement in base to give the corresponding 2-deamino-2-methyiamino folic acids 5 and 7, respectively. Amination of 2 with hydroxylamine-O-sulfonic acid in dilute base gave a low yield of 3-amino folic acid (8), which underwent Dimroth rearrangement to give 2-deamino-2-hydrazino folic acid (9) in an acidic, but not a basic, medium.     

Synthesis of polycyclic nitrogen‐containing heterocyclic: One pot formation of 1,6‐naphthyridine ring system by reaction of amino‐cyano‐methylthio‐heterocycles with dialkyl acetyeledicarboxylates

Reaction of 3‐amino‐3‐methylthio‐2‐cyanoacrylonitrile (1) with excess dimethyl acetylenedi‐carboxylate(DMAD) in the presence of potassium carbonate in dimethyl sulfoxide gave a novel tricyclic heterocycle, hexamethyl lH‐1,4,7‐triazaphenalene‐2,3,5,6,8,9‐hexacarboxylate ( 5a ). When one equivalent of DMAD was used in this reaction, dimethyl 4‐amino‐3‐cyano‐2‐methylthiopyridine‐5,6‐dicarboxylate ( 3a ), a key intermediate of 5a , was obtained.     

Oxidative carbomethoxylation of alkenes using a Pd(II)/molybdovanadophosphate (NPMoV) system under carbon monoxide and air

Oxidative carbomethoxylation of cyclopentene (1) under carbon monoxide and air by the use of a catalytic amount of Pd(OAc)(2) and molybdovanadophosphate (NPMoV) led to dimethyl cis-1,2-cyclopentanedicarboxylate (2) and dimethyl cis-1,3-cyclopentanedicarboxylate (3) in good yields. Total yields of 2 and 3 were found to be improved by adding a small amount of NH(4)Cl. Several alkenes were similarly converted into the corresponding dimethyl dicarboxylates. The role of Cl(-) in the present catalytic system is suggested.     

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。     

Silica Gel Catalyzed Conversion of Dimethyl 2-(5-Bromo-2-hydroxyphenyl)-3-(triphenylphosphoranylidene)butanedioate to Methyl 6-Bromo-2-oxo-2H-chromene-4-carboxylate in Solvent-Free Conditions

Protonation of the highly reactive 1:1 intermediates, produced in the reaction between triphenylphosphine and dimethyl acetylenedicarboxylate, by 4-bromophenol leads to vinyltriphenylphosphonium salt, which undergoes aromatic electrophilic substitution reaction with conjugate base to produce dimethyl 2-(5-bromo-2-hydroxyphenyl)-3-(triphenylphosphoranylidene)butanedioate. Silica gel was found to catalyze conversion of dimethyl 2-(5-bromo-2-hydroxyphenyl)-3-(triphenylphosphoranylidene)butanedioate to methyl 6-bromo-2-oxo-2H-chromene-4-carboxylate in solvent-free conditions at 80°C in fairly high yield.     

Practical and high stereoselective synthesis of 3-(arylmethylene)isoindolin-1-ones from 2-formylbenzoic acid

Practical and high stereoselective synthesis of 3-(arylmethylene)isoindolin-1-ones is reported. The synthetic method involves the preparation of dimethyl isoindolin-1-one-3-yl-phosphonates by a ‘one-pot’ three-component reaction of 2-formylbenzoic acid with 4-methoxybenzylamine or aminoacetaldehyde dimethyl acetal and dimethyl phosphite under solvent and catalyst free-conditions, followed by a Horner reaction with several aryl aldehydes.     

A new type of deoxygenation of quinoxaline N-oxides

The reaction of 6-chloro-2-[2-(p-chlorobenzylidene)-1-methylhydrazino]quinoxaline 4-oxide 3a or 2-[2-(p-bromobenzylidene)-1-methylhydrazino]-6-chloroquinoxaline 4-oxide 3b with dimethyl acetylenedicarboxylate under reflux in N,N-dimethylformamide resulted in deoxygenation to give 6-chloro-2-[2-(p-chlorobenzylidene)-1-methylhydrazino]quinoxaline 4a or 2-[2-(p-bromobenzilidene)-1-methylhydrazino]-6-chloroquinoxaline 4b , respectively, while the reaction of compound 3a or 3b with dimethyl acetylenedicarboxylate under reflux in dioxane precipitated dimethyl 8-chloro-4-[2-(p-chlorobenzyli-dene)-1-methylhydrazino]-3aH-isoxazolo[2,3-a]quinoxaline-2,3-dicarboxylate 6a or dimethyl 4-[2-(p-bromobenzylidene)-1-methylhydrazino]-8-chloro-3aH-isoxazolo[2,3-a]quinoxaline-2,3-dicarboxylate 6b , respectively. Further refluxing of compound 6a or 6b in N,N-dimethylformamide provided compound 4a or 4b , respectively.     

Sulfamic Acid–Catalyzed One‐Pot Synthesis of 3‐(4,6‐Dimethyl‐oxazolo[4,5‐c]quinolin‐2‐yl)‐chromen‐2‐ones using the Conventional Method and Microwave Irradiation

A rapid and efficient method for the preparation of 3‐(4,6‐dimethyl‐oxazolo[4,5‐c]quinolin‐2‐yl)‐chromen‐2‐ones by the reaction between 3‐amino‐2,8‐dimethyl‐quinolin‐4‐ol and 2‐oxo‐2H‐chromen‐3‐carboxylic acid using sulfamic acid as a acid catalyst and dimethyl formamide as a solvent using the conventional method and microwave irradiation is reported.     

Synthesis of octacarboxy spherosilicate

feasible new preparation was reported for an octacarboxylphenyl functionalized spherosilicate, octakis[(pcarboxyphenyl) dimethylsilyl]silicate, which was a versatile monomer leading to other functional spherosilicate derivatives. The synthesis was started from octakis[dimethyl(p-methylphenyl)silyl]silicate. Octakis[dimethyl(pmethylphenyl) silyl]silicate was brominated by NBS to produce octakis[dimethyl(4-tribromomethylphenyl)silyl]silicate. Finally, octakis[dimethyl(4-tribromomethylphenyl)silyl]silicate was hydrolyzed in the presence of AgNO3 and formic acid to give the desired compound. Octakis[(pcarboxyphenyl) dimethylsilyl]silicate was fully characterized by FTIR, 1H NMR, 13C NMR, 29Si NMR spectra, ESI-MS, and elemental analysis.     

2－甲基－3－芳基－7－（5，5－二甲基－3－酮－1－环己烯－1－基）甲酸酯－4（3H）－喹唑啉酮的合成

以2－氨基对苯二甲酸（1）为起始原料，与乙酸酐缩合生成7－羧基乙酰苯邻 甲内酰胺（2）；2和芳胺缩合产生7－羧基－2－甲基－3－芳基－4（3H）－喹唑啉 酮（3）；3和N，N－双环己基碳双亚胺（DCC）加成得到中间体4，4在4－二甲氨基 吡啶（DMAP）催化下和5，5－二甲基－1，3－环己二酮（5）缩合得到目标产物2－ 甲基－3－芳基－7－（5，5－二甲基－3－酮－1－环己烯－1－基）甲酸酯－4（ 3H）－喹唑啉酮（6）。所得15个新型化合物的结构均经^1H NMR、元素分析确证， 部分化合物经IC／MSD确证。