AZULENE-1-AZOPYRIDINES. SYNTHESIS AND N-ALKYLATION AT PYRIDINE MOIETY

Abstract

Azulene-1-azo-(3 0 -and 4 0 -pyridines) were synthesised from azulenes and diazotized aminopyridines. The mechanism for the generation of the diazonium salt was discussed. The obtained azulene-1-azo pyridines were alkylated with alkyl, benzyl and allyl halides. 825

2‐Substituted (Azulen‐1‐yl)ethenes

“…For the correct geometry assignment of compound 35, we recorded 1 H NMR spectra in the presence of increasing concentrations of [Eu(fod) 3 ] and we noted the displacement of the chemical shift belonging to the olefinic protons towards low field. This attests to the (Z) geometry of hydrogen and CO 2 H.…”

“…[2] From the synthetic point of view the reported compounds are important because they are the building blocks for the generation of complex molecular structures. [3] Recently, azulene derivatives, especially compounds belonging to these two classes, have been receiving increasing attention because of their valuable optical and electrochemical properties: as dyes, [4] for the elaboration of nonlinear optical (NLO) materials [5] or for the generation of chemically modified electrodes with polymeric films on their surfaces. [6] The results encouraged us to extend our investigations on the corresponding alkenes 1 (X ϭ Y ϭ CH).…”

Synthesis of azulenic compounds with a homo- or hetero-atomic double bond at position 1

“…H 3 PO 4 (85%), followed by coupling with azulenes in buffered medium (Scheme 41). 105 These results can be assigned to the formation of a complex 123 where the positive charge on 4-C is reduced by the polybasic acid which, thus, increases the stability of the azo group. Other polybasic acids, such as H 2 SO 4 or H 3 BO 3 have been also used, however, with lower success.…”

Synthesis of 5-nitropyridin-2-ylazo push-pull derivatives

“…Incorporation of π-deficient pyridine conserves the photoactivity of azobenzene and additionally provides the capability of self-assembly through H-bonding or metal coordination [3]. Although a number of investigations have been reported in the literature on pyridin-4-ylazo dyes [3][4][5][6], only a few pyridin-2-ylazo dyes have been synthesized [7,8], and to our knowledge no reports exist on 5-nitropyridin-2-yl-azo pushpull chromophore.The aim of the present study was to synthesize 5-nitropyridin-2-ylazobenzene derivatives 1a-c bearing in the electron-releasing part of the molecule a diethanolamino group [N(CH 2 CH 2 OH) 2 ] and an octyloxy group that efficiently, as our previous research shows [9], improve solubility and are expected to avoid the formation of undesirable centrosymmetric structures in the solid state. N N N N CH 2 CH 2 OH CH 2 CH 2 OH O 2 N R 1a-c a R = H, b R = OMe, c R = OC 8 H 17…”

“…Incorporation of π-deficient pyridine conserves the photoactivity of azobenzene and additionally provides the capability of self-assembly through H-bonding or metal coordination [3]. Although a number of investigations have been reported in the literature on pyridin-4-ylazo dyes [3][4][5][6], only a few pyridin-2-ylazo dyes have been synthesized [7,8], and to our knowledge no reports exist on 5-nitropyridin-2-yl-azo pushpull chromophore.…”