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Halochrome Molekeln 8. Mitteilung. Synthese und acidobasisches Verhalten von 3′‐substituierten 6,11‐Dihydrospiro[[1]benzopyrano[4,3‐ b ]indol‐6,9′−9′ H ‐xanthenen]
Author(s) -
Gunzenhauser Sigmund,
Balli Heinz
Publication year - 1989
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/hlca.19890720603
Subject(s) - chemistry , ring (chemistry) , mass spectrum , fragmentation (computing) , medicinal chemistry , stereochemistry , organic chemistry , chromatography , mass spectrometry , computer science , operating system
Halochromic Molecules. Synthesis and Acidobasic Properties of 3′‐substituted 6,11‐dihydrospiro[[1]benzopyrano[4,3‐ b ]indol‐6,9′−9′9′ H ‐xanthenes] We have synthesized a series of 3′‐substituted 6,11‐ihydrospiro[6 H ‐chromeno[4,3‐ b ]indol–6,9′−9′ H ‐xanthenes] and one of their respective aza analogues. 1 H‐MR data as well as the fragmentation in the mass spectra of starting and final products supported the postulated structures. With acid, the spiro compounds form ring‐opened intensely coloured xanthylium salts. UV/VIS spectra of these salts are listed and discussed. The ϵ pH* curves in buffered MeOH/H 2 O solutions and the pK * values are determined. The title compounds could possibly be used in ‘pressure sensitive papers’.