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v ‐Triazolines, XXIV. Pyrazolecarbaldehydes from 5‐Amino‐4,5‐dihydro‐4‐methylene‐ v ‐triazoles and Sydnones
Author(s) -
Destro Riccardo,
Erba Emanuela,
Forti Luciana,
Pocar Donato,
Scarcella Daniela
Publication year - 1985
Publication title -
liebigs annalen der chemie
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 0170-2041
DOI - 10.1002/jlac.198519850709
Subject(s) - chemistry , yield (engineering) , methylene , adduct , hydrolysis , medicinal chemistry , organic chemistry , stereochemistry , materials science , metallurgy
The sydnones 1a – c react with the 4,5‐dihydro‐ v ‐triazoles 2a – c by long refluxing at 110– 140°C affording via non‐isolable adducts with elimination of CO 2 and N 2 and rearrangement a mixture of 4,5‐dihydropyrazoles 3a – c , 3‐pyrazolecarbaldehyde anils 4a – d , and 3‐pyrazolecarbaldehydes 5a – c . Compounds 3 can be deaminated to give 4 which can be hydrolyzed to yield the 3‐pyrazolecarbaldehydes 5 .– The sydnones 6a, b react similarly with 2a to give a mixture of 4‐pyrazolecarbaldehyde anils 7a, b and 4‐pyrazolecarbaldehydes 8a, b . The structural assignments are based on spectroscopic and X‐ray diffraction data.