Synthesis of Some Heterocyclic Quaternary Amine Iodides.

Ditopic complex formation of the crown-containing 2-styrylbenzothiazole

“…Materials 2-Methylbenzothiazole (2), triphenylphosphine, phosphorus tribromide, 2-aminothiophenol, malonic acid were commercially available. 2,3,5,6,8,9,11,4,7,10,, (E)-3- (2,3,5,6,8, 9,11,12-octahydro-1,4,7,10,13-benzopentaoxacyclopentadecin-15-yl)-2-propenoic acid 8 ( 6), (1,3-benzothiazol-2-ylmethyl)-(triphenyl)phosphonium bromide 4 (3), 3-methyl-1,3-benzothiazol-3-ium iodide 7 were synthesized according to known procedures.…”

“…Heating reactants 2 and 4 with concentrated HCl at 100-130 C for 3 h results in compound 1 in 23% yield, and some resinification occurs in course of the process (Method C, Scheme 1). The dye 6 6 was obtained by reaction of 2,3-dimethylbenzothiazolium iodide 7 with 4 in boiling ethanol containing Py as a catalyst. Dye 6 produces 1 in 47% yield upon heating with PPh 3 (Method D, Scheme 1).…”

“…The hypsochromic or bathochromic shifts observed upon complex formation in crown-containing stilbene-like molecules can be explained by changes in electronic interactions, as discussed in detail in some previous publications. 10a-e When a chromophore contains an electron-donating group conjugated to an electron-withdrawing group, it undergoes intramolecular charge transfer from the donor to the acceptor upon excitation 12) benzene ring fragment of the benzocrown ether exhibits a distinct bond alternation (1.381( 8), 1.413 (7), 1.374( 7), and 1.419( 7) A ˚, respectively), whereas the C( 14)-C( 13)-C( 12) fragment shows almost complete bond delocalisation (1.392( 8), and 1.398(8) A ˚). This peculiarity may be due to a weak coordination of the C( 12)-C( 13)-C( 14) fragment to the Ag(1) atom of the adjacent formula unit in the crystal packing (see below).…”

“…The Ag(1) atom is coordinated with the five crown ether oxygen atoms [Ag(1)Á Á ÁO bond lengths varying in the range 2.426(4)-2.721(4) A ˚] and the O( 6) oxygen atom [2.367(4) A ˚] of the nitrate group. An irregular bidentate type coordination of the nitrate group could be considered too [the AgÁ Á ÁO (7) distance is equal to 2.661(4) A ˚]. The interaction of Ag(NO 3 ) moiety with 18-crown-6 was investigated previously in our theoretical work.…”

Synthesis and spectroscopic studies of novel photochromic benzodithiacrown ethers and their complexes

“…(4-Formylbenzo)-l8-crown-6 (2) and the iodide of 2,3dimethylbenzothiazolium (4) were obtained as described p r e v i ~u s l y . ~~~ We have devised new synthetic routes to compounds 5 , 6 and 11. To prepare the N-(hydroxycarbonylalkyl)-2-methylbenzothiazolium salts (5, 6), 2-methylbenzothiazole was fused with the corresponding bromocarboxylic acid at 120 "C. In the case of 5-bromovaleric acid 6 was obtained, but the yield in this reaction was low because of a parallel reaction resulting in the formation of the corresponding Due to the complication of lactone formation, we have attempted to obtain 5 by quaternization of 2-methylbenzothiazole with ethyl 4-bromobutyrate followed by hydrolysis of the ester in acid medium.…”