Synthesis of 4-hetaryl-5,6-(2,5-dimethyl-3-thienyl)-2-phenyl-4h-thiazines and investigation of their photochromism

The polar [4+2] cycloaddition reaction of 1,2-bis(2,5-dimethyl-3-thienyl)acetylene with thiobenzamide and certain aldehydes of the thiophene and furan series catalyzed by boron trifluoride etherate gives the corresponding 4-hetaryl-5,6-di(2,5-dimethyl-3-thienyl)-2-phenyl-4H-1,3-thiazines. The photochromic properties of the products have been studied.__________Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 100–106, January, 2005.     

Synthesis of 3,4-bis(2,5-dimethyl-3-thienyl)furan-2,5-dione from mucobromic acid

Palladium-catalyzed cross-coupling between 2,5-dimethyl-3-thienylboronic and mucobromic acids under phase transfer catalysis (PTC) conditions gave the expected 3,4-bis(2,5-dimethyl-3-thienyl)-5-hydroxyfuran-2-one in 32% yield. The by-product was 2,2’,5,5’-tetramethyl-3,3’-bithiophene. The oxidation of the obtained hemiacylal with potassium permanganate under PTC conditions afforded 3,4-bis(2,5-dimethyl-3-thienyl)furan-2,5-dione in high yield.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 2238–2240, October, 2004.     

Photochromic Dihetarylethylenes. 22. Synthesis and Photochromic Properties of Unsymmetrical Alkylthio-substituted 1,2-Bis(dithienyl)perfluorocyclopentenes

Certain unsymmetrical 1,2-bis(dithienyl)perfluorocyclopentenes have been synthesized containing alkylthio, bromo, carboxy, and benzothiazolyl substituents in the thiophene rings. It was shown that on irradiation with UV light they all display photochromic properties, with the exception of the derivative containing an alkylthio group in the reaction center of one of the thiophene rings.For the anniversary of Academician N. K. Kochetkov.__________Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 691–696, May, 2005.     

A Simple Approach to the Synthesis of 1,4-Bis(arylsulfonyl)tetrahydropyrazine-2,5-diones

Summary.  The addition of triphenylphosphine to dimethyl acetylenedicarboxylate in the presence of arylsulfonylglycyl chlorides leads to 1,4-bis-arylsulfonyl-tetrahydropyrazine-2,5-diones and dimethyl (E)-2-chloro-2-butenedioate. Corresponding author. E-mail: isayavar@yahoo.com Received June 3, 2002; accepted June 10, 2002     

L-Proline-Catalyzed Synthesis of Novel 5-(1H-Indol-3-yl-methylene)-thiazolidine-2,4-dione Derivatives as Potential Antihyperglycemic Agents

Knoevenagel condensation between indole-3-aldehyde 1 and an active methylene group containing 2,4-thiazolidinedione 2 in refluxing toluene using L-proline as a catalyst yielded 3, which on alkylation using 2 equivalents of alkylating agent under phase-transfer-catalyzed (PTC) conditions using K₂CO₃ as a base in dimethylformamide gave N,N^I-symmetrically disubstituted 5-(1H-indol-3ylmethylene)-thiazolidine-2,4-diones 4. Alternately, 4 can be synthesized by condensing 5 and 6 in a single step. Using this synthetic strategy, N,N^I-unsymmetricallydisubstituted derivatives 9a–f were prepared either by condensing 6 with N-substituted-2,4-thiazolidinedione 5 to obtain 7 followed by alkylation under PTC conditions or condensing 6 with N-unsubstituted- 2,4-thiazolidinedione 2 to yield 8 followed by alkylation under PTC conditions. The latter are the dehydro analogs of the dihydro-N-substituted-5-(1H-indol-3-yl-methylene)-thiazolidine-2,4-diones, which are potential antihyperglycemic agents.

Cyclization of vicinally substituted heterocyclic analogs of 3,4-bis(indol-1-yl)maleimide under the action of protic acids: a quantum chemical study

B3LYP/6-31G(d) density functional quantum chemical calculations of vicinally substituted bis(indol-1-yl)derivatives of 1,5-dihydropyrrol-2-one, furan-2,5-dione, cyclopent-4-ene-1,3-dione, cyclobut-3-ene-1,2-dione, and pyrrolidine-2,5-dione were carried out to study the effect of modification of the maleimide moiety in 3,4-bis(indol-1-yl)maleimides on the direction of intramolecular cyclization under the action of protic acids. Geometric parameters, charge distributions, energy characteristics, and frontier orbital energies of these compounds and the corresponding indoleninium cations were determined. Alternative protonation routes of 3,4-bis(indol-1-yl)-1,5-dihydropyrrol-2-one have been studied. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1348–1352, July, 2008.     

Synthesis, Crystal Structure and Property of a Series of Supramolecular Polymers Based on Novel 3,5-Dimethyl- 2,6-bis（3-（pyrid-2-yl）-1,2,4-triazolyl）pyridine Ligand

Solvothermal reactions of 3,5-dimethyl-2,6-bis(3-(pyrid-2-yl)-1,2,4-triazolyl) pyridine (L), 1,4-benzendicarboxylic acid (H2bdc), and transitional metal cations of MII (M = Mn, Co, Cd) in the presence of oxalic acid (H2ox) afford three novel supramolecular polymers (CPs), namely, {[M2(ox)(L)2][bdc][M2(Hox)2(OH)2(H2O)4].3H2O}n (M=Mn for 1, Co for 2, Cd for 3). Single-crystal X-ray diffraction analysis reveals that complexes 1-3 are isostructural and the 3D supramolecular structure was connected through non-covalent interactions. With the help of H2ox, the L ligands cheated with center atoms forming a butterfly [M2(ox)(L)2]2+ building block. The bdc2- ligand linked with the unprecedented [M2(Hox)2(OH)2(H2O)4] units through strong O-H…O hydrogen bonds forming a zigzag chain, which are further connected through π…π interactions between L and bdc2- ligands to form a 3D supramolecular structure. Moreover, elemental analyses, IR, thermogravimetric, PXRD and luminescence have been investigated.     

A reinvestigation of the reactions of 3-substituted chromones with hydroxylamine. Unexpected synthesis of 3-amino-4H-chromeno[3,4-d]isoxazol-4-one and 3-(diaminomethylene)chroman-2,4-dione

Reactions of 3-substituted chromones (3-formylchromone, 3-formylchromone-3-oxime, and 3-cyanochromone) with hydroxylamine in alkaline medium were reinvestigated, and a proof of structures and a probable reaction pathway are presented. Syntheses of 2-aminochromone-3-carboxamide, 3-amino-4H-chromeno[3,4-d]isoxazol-4-one, and 3-(diaminomethylene)chroman-2,4-dione were developed.     

Photochromic Dihetarylethylenes. 21. Synthesis and Photochemical Properties of 1,2-Bis{5-(2-benzothiazolyl)-2-ethylthieno-[2,3-<Emphasis Type="Italic">b</Emphasis>]thiophen-3-yl}Hexafluorocyclopentene

1,2-Bis{5-(2-benzothiazolyl)-2-ethylthieno[2,3-b]thiophen-3-yl}hexafluorocyclopentene has been synthesized for the first time. It was shown that, unlike analogous derivatives of thieno[3,2-b]thiophene, on irradiation with UV light (λ = 313 nm) it did not display photochromic properties, but undergoes an irreversible photoconversion which is accompanied by the display of intense fluorescence. This raises the prospect of using this compound for creating an irreversible photoluminescent recording medium.Dedicated to V. I. Minkin on his 70th birthday.__________Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 360–364, March, 2005.For Part 20 see [1].     

Purines, pyrimidines, and related fused systems. 21. Oxidative amination of 3-chloro-6,8-dimethylpyrimido[4,5-c]pyridazine-5,7(6H,8H)-dione

Oxidative amination of 3-chloro-6,8-dimethylpyrimido[4,5-c]pyridazine-5,7(6H,8H)-dione with primary alkylamines and potassium amide in liquid ammonia gives rise to the corresponding 4-amino derivatives as the major products. The reactions with acyclic secondary amines are accompanied by annelation of the pyrrole moiety to the starting heterosystem to form 1-R-3-R"-6,8-dimethylpyrrolo[2",3";3,4]pyrimido[4,5-c]pyridazine-7,9(6H,8H)-diones. The reaction with piperidine as the aminating agent occurs exclusively as aminodehalogenation. The Sonogashira cross-coupling of 4-amino-3-chloro-6,8-dimethylpyrimido[4,5-c]pyridazine-5,7(6H,8H)-diones with terminal alkynes affords 1-R-2-R"-6,8-dimethylpyrrolo[3",2";3,4]pyrimido[4,5-c]pyridazine-7,9(6H,8H)-diones.     

4-氟苯甲醛、β-萘胺和Meldrum酸-锅反应生成1-(4-氟苯基)-1,2-二氢苯并[f]喹啉-3(4H)-酮的反应机理理论研究

采用密度泛函理论(DFT)研究了4-氟苯甲醛、β-萘胺和Meldrum酸一锅反应生成1-(4-氟苯基)-1,2-二氢苯并[f]喹啉-3(4H)-酮的微观反应机理.在B3LYP/6-311G*基组水平上优化了反应物、过渡态、中间体及产物的几何构型,通过振动分析确认了过渡态的结构,并用内禀反应坐标(IRC)确认反应途径.应用分子中的原子理论(AIM)分析了这些物质的成键特征.采用SCRF(PCM)方法研究了反应体系的溶剂化效应.报道了可能的反应路径,其中Re→TS1→IM1→TS2→IM2→TS3→IM3→TS4→IM5→TS7→IM9→TS13→IM10→TS14→P3具有相对较低的活化能,是反应的主要通道,理论预测的主要产物与实验吻合.     

N-Chlorophthalimide as a mild and efficient chlorination reagent in the Gassman ortho alkylation of aromatic amines. Synthesis of 3-(methylthio)oxindoles

A practical modification of the Gassman 3-(methylthio)oxindole synthesis is reported. In our method, substituted anilines and 2-(methylthio)acetamide were reacted under mild reaction conditions, in the presence of N-chlorophthalimide as a chlorinating agent to give α-amidosulfides, which, in the next step of the process, were cyclized to give 3-(methylthio)oxindoles. The method was successfully applied for the synthesis of the key intermediate, 2-(2-amino-3-benzoylphenyl)-2-(methylthio)acetamide, in the process of the preparation of nepafenac, a commonly used ophthalmic drug.     

4-氟苯甲醛、β-萘胺和Meldrum酸一锅反应生成1-(4-氟苯基)-1,2-二氢苯并[f]喹啉-3(4H)-酮的反应机理理论研究

采用密度泛函理论(DFT)研究了4-氟苯甲醛、β-萘胺和Meldrum酸一锅反应生成1-(4-氟苯基)-1,2-二氢苯并[f]喹啉-3(4H)-酮的微观反应机理.在B3LYP/6-311G*基组水平上优化了反应物、过渡态、中间体及产物的几何构型,通过振动分析确认了过渡态的结构,并用内禀反应坐标(IRC)确认反应途径.应用分子中的原子理论(AIM)分析了这些物质的成键特征.采用SCRF(PCM)方法研究了反应体系的溶剂化效应.报道了可能的反应路径,其中Re→TS1→IM1→TS2→IM2→TS3→IM3→TS4→IM5→TS7→IM9→TS13→IM10→TS14→P3具有相对较低的活化能,是反应的主要通道,理论预测的主要产物与实验吻合.     

Limitations of the Wittig-Horner-type annulation of fluorobutenolide moiety to 3-hydroxyquinoline-2,4(2H,3H)-diones. Novel modifications of the Perkow reaction including fluorinated acyloxy leaving groups

3-(Fluoroacyloxy)quinoline-2,4(1H,3H)-diones react with triethyl phosphite to afford either the product of the Perkow reaction or the corresponding 4-ethoxyquinolin-2(1H)-one. In both reactions, the fluorocarboxylate anion acts as the leaving group. For the corresponding 3-(fluoroiodoacetoxy) derivative this observation precludes the application of the intramolecular Wittig-Horner synthesis to modify quinoline-2,4(1H,3H)-diones by the annulation of a fluorinated but-2-enolide moiety.     

Pheromone synthesis. Part 244: Synthesis of the racemate and enantiomers of (11Z,19Z)-CH503 (3-acetoxy-11,19-octacosadien-1-ol), a new sex pheromone of male Drosophila melanogaster to show its (S)-isomer and racemate as bioactive

The enantiomers of (11Z,19Z)-3-acetoxy-11,19-octacosadien-1-ol were synthesized from the enantiomers of 3,4-epoxy-1-butanol PMB ether. Its racemate was also synthesized. Its (S)-isomer and racemate were shown to possess the same pheromone activity as CH503, a long-lived inhibitor of male courtship in Drosophila melanogaster, although the racemate was less active.