Photochromic Dihetarylethenes. 8. A Novel Route to the Synthesis of 3,4-Bis(2,5-dimethyl-3-thienyl)furan-2,5-dione as a Potential Photochrome

There is proposed, and in the case of 2,5-dimethylthiophene carried out, a novel route to the synthesis of 3,4-dithienylfuran-2,5-dione type photochromes. This is done in two stages, the first being a Friedel-Crafts reaction of the starting thiophene with the dichloride of squaric acid and the second is a Baeyer-Villiger oxidation of the 3,4-bis(2,5-dimethyl-3-thienyl)cyclobutenedione to give the target 3,4-bis(2,5-dimethyl-3-thienyl)furan-2,5-dione.     

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 Substituted 1,2,4-Triazines Based on 1,2-Bis(2,5-dimethyl-3-thienyl)ethanedione

A novel, convenient method has been developed for the synthesis of 1,2-bis(2,5-dimethyl-3-thienyl)ethanedione, from which were prepared 5,6-bis(2,5-dimethyl-3-thienyl)-1,2,4-triazines (analogs of the photochromic 1,2-diarylethenes). The principial possibility of using 1,2,4-triazines obtained as photochromic agents was investigated.     

Photochromic Dihetarylethenes: XVII. New Synthesis of Photochromic N-Alkyldithienylmaleimides

A new convenient procedure for the synthesis of photochromic N-alkyldithienylmaleimides was developed on the basis of the reaction of 3,4-bis(2,5-dimethyl-3-thienyl)furan-2,5-dione with primary amines. Photochromic properties of the products were examined.     

Photochromic Dihetarylethenes: XX. Synthesis and Photochromic Properties of Dithienylethenes with a Fixed Conformation

>A procedure was developed for the synthesis of bis(2,5-dimethyl-3-thienyl)ethenes with partially fixed molecular conformation, and their photochromic properties in solution were studied. The structure of photochromic 1-(2,5-dimethyl-3-thienyl)-7,9-dimethyl-5,6-dihydrothieno[3',4' : 3,4]pyrido[1,2-c][1,3]oxazol-3-one, as well as of 1-(2,5-dimethyl-3-thienyl)-7,9-dimethylthieno[3',4' : 3,4]pyrido[1,2-c][1,3]oxazol-3-one possessing no photochromic properties, was determined by X-ray analysis.     

Synthesis of 2,5 -Bis(4-methyl-2-thienyl)thiophene and 2,5-Bis(4-methyl-2-thienyl)pyrrole

Syntheses of 2,5-bis(4-methyl-2-thienyl)thiophene 3 and 2,5-bis(4-methyl-2-thienyl)pyrrole 4 are described. The key step involves Stetter reaction between 4-methyl-2-thiophenecarboxaldehyde and divinyl sulfone. Cyclizaton of the resulting 1,4-bis-(4-methyl-2-thienyl)-1,4-butanedione 2 with Lawesson's reagent gives 2,5-bis(4-methyl-2-thienyl)thiophene 3, whereas condensation with ammonium acetate provides the 2,5-bis(4-methyl-2-thienyl)pyrrole 4.     

Synthesis and photochromic properties of tetrakis(3,5-dimethyl-2-thienyl)- and tetrakis(2,5-dimethyl-3-thienyl)ethylenes

Tetrakis(3,5-dimethyl-2-thienyl)ethylene and tetrakis(2,5-dimethyl-3-thienyl)ethylene were obtained from the corresponding dithienyl ketones by the McMurry reaction. The photochromic properties of the compounds obtained were studied. Dedicated to the Academician N. K. Kochetkov on the occasion of his 90th birthday. __________ Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 1177–1181, May, 2005.     

Synthesis of benzoates of 1,4-bis(2,5-dimethyl-4-hydroxypiperidino)-2-butene and 1,4-bis-(2,5-dimethyl-4-hydroxypiperidino)-2-butyne

1,4-Bis(2,5-dimethyl-4-hydroxypiperidino)-2-butene and 1,4-bis(2,5-dimethyl-4-hydroxypiperidino)-2-butyne (II and III) were obtained by the action of 1,4-dibromo-2-butene and 1,4-dibromo-2-butyne on the form of 2,5-dimethyl-4-piperidol (I). The benzoates (IV and V) were obtained by acylation of II and III with benzoyl chloride.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 352–353, March, 1971.     

Photochromic dihetarylethenes. 13. Optimization of conditions for the acylation of 2,5-dimethylthiophene with squaric acid dichloride

The conditions for acylation of 2,5-dimethylthiophene with squaric acid dichloride were optimized, and 3,4-bis(2,5-dimethylthiophen-3-yl)cyclobut-3-ene-1,2-dione was obtained in good yield. X-ray diffraction analysis demonstrated that the by-product has the structure of 1a,1b-dichloro-5-(2,5-dimethylthiophen-3-yl)-3-hydroxy-4,5a-dimethyl-1b,4a,5,5a-tetrahydro-1aH-1-thiacyclopropa[a]pentalen-2-one.     

On the syntheses and some reactions of bis- and tris(methylthio)thiophenes

Reaction between various thienyllithium derivatives and dimethyl disulfide has been used for the preparation of 2,5-, 2,3-, and 3,4-bis(methylthio)thiophenes, as well as 2,3,4- and 2,3,5-tris(methylthio)thiophenes. Bromination of (methylthio)thiophenes with N-bromosuccinimide was found to be most convenient for the preparation of brominated (methylthio)thiophenes such as 3-bromo-2,5-bis(methylthio)- and 5-bromo-2,3-bis(methylthio)thiophene, 3,4-dibromo-2,5-bis(methylthio)-, 2,5-dibromo-3,4-bis(methylthio)- and 2,3-dibromo-4,5-bis(methylthio)thiophene as well as 3-bromo-2,4,5-tris(methylthio)thiophene. The reaction of methylthio substituted thienyllithium derivatives with methyl chloroformate was used for the syntheses of methyl methylthio substituted thiophenecarboxylates and using 1/3 of an equivalent for the direct preparation of methylthio substituted 3-thienylcarbinols as tris[2,4,5-tris(methylthio)-3-thienyl]carbinol.     

Photochromic dihetarylethenes. 17. Synthesis and photochromic properties of dithienylethenes containing new heterocyclic bridging fragments

Procedures were developed for the synthesis of substituted bis(2,5-dimethyl-3-thienyl)ethenes containing the imidazol-2-one, 1,3-dioxol-2-one, or 1,3-oxazol-2-one fragments as ethene bridges. These compounds were demonstrated to exhibit the photochromic properties. The cyclic forms of some imidazolone and oxazolone photochromes possess high thermal stability. The structure of photochromic 4,5-bis(4-acetyl-2,5-dimethyl-3-thienyl)-3-methyl-2,3-dihydro-1,3-oxazol-2-one was established by X-ray diffraction analysis. The molecule adopts an anti-parallel conformation similar to that of perfluorocyclopentene-bridged dithienylethenes.     

Photochromic dihetarylethenes. 11. Synthesis and photochromic properties of diarylethenes containing furan or furopyrimidine bridges

Procedures were developed for the synthesis of substituted bis(2,5-dimethyl-3-thienyl)furans based on 1,2-bis(2,5-dimethyl-3-thienyl)-2-hydroxyethanone. Dithienylethene structures in which the ethene fragment is involved in the furan or furopyrimidine system possess photochromic properties and their open forms exhibit fluorescence.     

Synthesis and michael reaction of 3,4-dimethylpyrrole

A two step synthesis of 3,4-dimethylpyrrole via the reduction of 3-carboethoxy-4-methyl-pyrrole is described. Michael addition of methyl vinyl ketone and butyn-2-one to 3,4-dimethylpyrrole gives the bisadducts, 2,5-bis(3-oxobutyl)-3,4-dimethylpyrrole and 2,5-bis(3-oxobutenyl)-3,4-dimethylpyrrole, respectively, while ethyl propiolate affords only the monoadduct, ethyl 3-(3,4-dimethylpyrrol-2-yl)propenoate. Catalytic reduction of the latter ester gives ethyl 3-(3,4-dimethylpyrrol-2-yl)propanoate which with ethyl propiolate gives ethyl 3-(5-carbethoxyethyl-3,4-dimethyl-2-yl)propenoate.     

Synthesis and Structure of 5-Indolyl-6-thienyl-1,2,4-triazines

Acylation of indole and 2,5-dimethylthiophene with 2-(3-indolyl)-2-oxoacetyl chloride afforded the corresponding diketones. 1-(2,5-Dimethyl-3-thienyl)-2-(3-indolyl)ethanedione reacted with thiosemicarbazide under atmosperic and elevated pressure to give 6-(2,5-dimethyl-3-thienyl)-5-(3-indolyl)-2,3-dihydro-1,2,4-triazine-3-thione whose structure was studied in detail by the X-ray diffraction method. Reactions of 6-(2,5-dimethyl-3-thienyl)-5-(3-indolyl)-2,3-dihydro-1,2,4-triazine-3-thione with amines and hydrazine resulted in formation of fused triazolo- and tetrazolotriazines.__________Translated from Zhurnal Organicheskoi Khimii, Vol. 41, No. 6, 2005, pp. 895–902.Original Russian Text Copyright © 2005 by Krayushkin, Yarovenko, Sedishev, Zavarzin, Vorontsova, Starikova.Dedicated to Full Member of the Russian Academy of Sciences V.I. Minkin on his Jubilee     

Electrochemical preparation of polythiophene via 2,5-bis(trimethylsilyl)thiophene

Electrochemical polymerization of 2,5-bis(trimethylsilyl) thiophene produced highly conducting films which showed infrared spectra, visible-near infrared absorption spectra, and cyclic voltammograms identical to films prepared from thiophene. Elemental analysis indicated that almost all silicon atoms were eliminated during the electrochemical polymerization. However, scanning electron microscopy showed a morphological difference between the films from 2,5-bis(trimethylsilyl)thiophene and from thiophene. The electrochemical polymerization of bis(2-thienyl)dimethylsilane, 1,2-bis(2-thienyl)tetramethyldisilane, and bis(2-thienyl)diphenylsilane also produced polythiophene films having unique morphologies quite different from the conventional ones. These findings indicate that these electrochemical procedures must be useful for preparation of new conjugated polymers. © 1992 John Wiley & Sons, Inc.     

Hydroxymethylation of methyl-substituted pyrrole,thiophene, and furan in the presence of H+ cation exchangers

In the reaction of formalin with the 2,5-dimethyl derivatives of pyrrole, thiophene, and furan in the presence of the sulfo cation exchanger Amberlyst 15 electrophilic substitution takes place at various positions of the rings with the formation of 2,5-dimethyl-1-hydroxymethylpyrrole, 1,3-dioxacycloheptano[5,6-c]-2,5-dimethylthiophene (an intermediate in the formation of which is 2,5-dimethyl-3,4-dihydroxymethylthiophene), and 2,5-hexanedione respectively. Bis(5-methyl-2-thienyl)methane was obtained from 2-methylthiophene.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1640–1643, December, 1991.     

Cyanoacetylene and Its Derivatives: XXXIII. One-Pot Stereoselective Synthesis of Bis-iminodihydrofurans from 4-Hydroxy-4-methyl-2-pentynonitrile and Aromatic Amines

4-Hydroxy-4-methyl-2-pentynonitrile reacts with aniline, N-methylaniline, and 2-naphthylamine under mild conditions (20–80°C) to afford the corresponding 4-arylamino-2-(2-imino-5,5-dimethyl-2,5-dihydro-4-furylimino)-5,5-dimethyl-2,5-dihydrofurans in one preparative step. According to the X-ray diffraction data, both imino groups in the products have syn configuration with respect to the ring oxygen atom.__________Translated from Zhurnal Organicheskoi Khimii, Vol. 41, No. 6, 2005, pp. 903–909.Original Russian Text Copyright © 2005 by Trofimov, Mal’kina, Shemyakina, Kudyakova, Sokolyanskaya, Sinegovskaya, Albanov, Smirnov, Kazheva, Chekhlov, D’yachenko.     

Multicolor photochromism of two- and three-component diarylethene crystals

Novel photochromic single crystals composed of three different kinds of diarylethenes, 1,2-bis(3,5-dimethyl-2-thienyl)perfluorocyclopentene (1a), 1,2-bis(2,5-dimethyl-3-thienyl)perfluorocyclopentene (2a), and 1,2-bis(2-methyl-5-p-methoxyphenyl-3-thienyl)perfluorocyclopentene (3a), have been prepared. The three-component crystals turned yellow, orange, red, purple, blue, green, or black upon irradiation with light of appropriate wavelengths. The colors of the crystals were thermally stable in the dark and completely bleached by irradiation with visible light. Such multicolored photochromic crystals have potential for the application to optoelectronic devices, such as multifrequency three-dimensional optical memory media or full-color displays.     

Synthesis and reactivity of germanium heterocycles containing germanium-tin bonds

Previously unknown stannyl-substituted germanium heterocycles, 1, 1 -bis(trimethylstannyl) 2,3,4,5-tetraphenyl-l-germacyclopenta-2,4-dienc and 1,1-bis(trimethylstannyl)-3,4-dimethyl-1-germacyclopent-3-ene were synthesized, and their photolysis and chemical transformations were Studied.Translated fromIzvestiya Akademii Nauk, Seriya Khimicheskaya, No. 11, pp 2764–2767, November, 1996.     

Three bits eight states photochromic recording and nondestructive readout by using IR light

A photochromic polymer film containing three different diarylethene derivatives, that is, 1,2-bis(3,5-dimethyl-2-thienyl)perfluorocyclopentene (1), 1,2-bis(2,5-dimethyl-3-thienyl)perfluorocyclopentene (2), and 1,2-bis(2-methyl-5-phenyl-3-thienyl)perfluorocyclopentene (3) was prepared. Upon UV irradiation, the three derivatives changed to their closed-ring isomers having different colors, yellow, red, and blue. They showed different spectra not only in UV/Vis region but also in the IR spectral region. Upon irradiation with visible light of appropriate wavelengths, each closed-ring isomer was selectively bleached, and three bits eight states recording was performed. The eight states could be read out nondestructively by using IR light of appropriate wavenumbers.