Polymethylene dyes derived from heterocyclic bases containing condensed thiophene rings

Some new polymethine dyes of the cyanine and merocyanine series which are derivatives of 5- and 6- thienopyridines are synthesized. Replacement of a vinyl group at a sulfur atom in the condensed benzene ring of quinoline in dyes which are derivatives of this base, always leads to a bathochromic shift of the absorption maximum of the corresponding dyes.     

Methyl-substituted heterocyclic bases containing condensed selenonaphthene rings

The synthesis of 2-methylselenonaphtheno[2,3-d]thiazole and 2-methylselenonaphtheno[2,3-d]-oxazole is described.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 37–38, January, 1971.     

Synthesis of 2-methyl-5-phenylthieno[2,3-d]thiazole

The synthesis of a new heterocyclic base — 2-methyl-5-phenylthieno[2,3-d]thiazole — is described.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, 1624–1625, December, 1970.     

Synthesis of 7-methyl- and 9-methylthieno[3, 2-f]quinoline

New heterocyclic bases with a condensed heterocyclic ring in the molecule are synthesized. They are 7-methylthieno[3, 2-f ]quinoline and 9-methylthieno[3, 2-f]quinoline.     

Synthesis of 2-methylthie no [3,2-b]thieno-[2,3-d]thiazole

A new heterocyclic base — 2-methylthieno[3,2-b]thieno[2,3-d]thiazole — was synthesized by heating 2-acetamido-3-hydroxythieno[3,2-b]thiophene with phosphorus pentasulfide.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1039–1041, August, 1976.     

Polymethine dyes which are derivatives of heterocyclic bases containing condensed thiophene rings

Some new polymethine dyes of the cyanine and merocyanine series, containing thieno[2, 3-b]thieno[2, 3-b]pyridine-4 and thieno[3, 2-b]-thieno[2, 3-b]-pyridine-8 groups are synthesized. Replacement of the vinylene group by a sulfur atom in the condensed benzene rings of the 5, 6-benzoquinoline-4 group in dyes which are derivatives of this base, results in a marked hypsochromic shift of the absorption maximum of the corresponding dyes.For Part IV see [8].     

Synthesis of methyl-substituted pyrano-thiapyrano-, and selenapyrano[2,3-b]pyridines

2H-Pyrano-, 2H-thiapyrano-, and 2H-selenapyrano[2,3-b]pyridines containing a methyl group in the position of the pyridine ring were synthesized by Claisen condensation of the ethyl esters of, respectively, 2-ethoxy-, 2-ethylthio-, and 2-ethylseleno-6-methylpyridine-3-carboxylic acids with ethyl acetate, reduction of the resulting ethyl esters of 2-ethoxy-, 2-ethylthio-, and 2-ethylseleno-6-methylnicotinoylacetic acids with lithium aluminum hydride, and heating of the resulting 2-substituted 3-(, -dihydroxypropyl)-6-methylpyridines with 48% hydrobromic acid.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1539–1540, November, 1972.     

Synthesis of 4,4,5-trimethylthieno[2,3-b]pyrrolenine and 5,6,6-trimethylthieno[3,2-b]pyrrolenine

New heterocyclic bases—4,4,5-trimethylthieno[2, 3-b]pyrrolenine and 5, 6, 6-trimethylthieno[3,2-b]pyrrolenine—have been obtained by the condensation of the double salts of stannic chloride and the hydrochlorides of, respectively, 2- and 3-aminothiophenes with methyl-hydroxyisopropyl ketone and methyl-bromoisopropyl ketone.     

Polymethine dyes — Furo[3,2-f]quinol-7-yl and furo[3,2-f]quinol-9-yl derivatives

New heterocyclic bases — 7- and 9-methylfuro[3,2-f]quinolines — were synthesized by condensation of 5-aminobenzofuran double tin hydrochloride salt with paraldehyde in dilute hydrochloric acid and with methyl vinyl ketone in ethanol in the presence of ferric chloride and zinc chloride. Polymethine dyes of various types were obtained from the quaternary salts of the synthesized bases. The introduction of a furan ring in the 5,6 position of quino-2- and quino-4-carbocyanines gives rise to a smaller bathochromic effect than the analogous introduction of a thieno and, particularly, a benzo group.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 391–394, March, 1977.