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Reactions of methylpyrylium, thiapyrylium, and flavylium salts with tetracyanoethylene
Author(s) -
Haley N. F.
Publication year - 1977
Publication title -
journal of heterocyclic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.321
H-Index - 59
eISSN - 1943-5193
pISSN - 0022-152X
DOI - 10.1002/jhet.5570140721
Subject(s) - tetracyanoethylene , chemistry , yield (engineering) , pyridine , salt (chemistry) , methylene , perchlorate , medicinal chemistry , photochemistry , organic chemistry , ion , materials science , metallurgy
The reaction of 2‐ or 4‐methyl‐2,6‐diphenylpyrylium perchlorate with tetracyanoethylene (TCNE) in pyridine gives 2‐ or 4‐(2,3,3‐tricyanopropylidene)‐2,6‐diphenylpyran in good yield. Similar results are obtained from 2‐ or 4‐methyl‐2,6‐diphenylthiapyrylium and 4‐methylflavylium perchlorates. In one case a stable charge‐transfer salt is isolated from the reaction of a methylene base and TCNE. The reaction mechanism of dye formation is discussed.