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Photochemisches Verhalten von 3,4‐Diarylsydonen . Vorläufige Mitteilung
Author(s) -
Märky M.,
Hansen H.J.,
Schmid H.
Publication year - 1971
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.19710540506
Subject(s) - chemistry , sydnone , indene , irradiation , medicinal chemistry , photochemistry , acetylene , yield (engineering) , organic chemistry , ring (chemistry) , physics , materials science , nuclear physics , metallurgy
3, 4‐Diphenyl‐sydnone ( 1a ) and 3‐ p ‐tolyl‐4‐phenyl‐sydnone ( 1b ) on irradiation with a mercury high‐pressure lamp in pyrex vessels yield 2,4,5‐triphenyl‐ ( 3a ) and 2‐ p ‐tolyl‐4,5‐diphenyl‐1,2,3‐triazole ( 3b ), respectively. Irradiation of 1a and 1b in the presence of dimethyl acetylene‐dicarboxylate or indene leads to the formation of the pyrazoles 4a and 4b and the Δ 2 ‐pyrazolines 5a and 5b , respectively. Reactive intermediates of the photoreaction of 1a and 1b seem to be the diazirines 2a and 2b , which open to give the 1,3‐dipolar structures 8a and 8b .