76878-01-8Relevant academic research and scientific papers
Studies on the Synthesis of Heterocyclic Compounds. Part IV. Further Investigation of the Pschorr Reaction with Some Pyrazole Derivatives
Daidone, Giuseppe,Plescia, Salvatore,Fabra, Jole
, p. 1409 - 1411 (2007/10/02)
Thermal decomposition of the diazonium sulfate derived from N-methyl-(1-phenyl-3-methylpyrazol-5-yl)-2-aminobenzamide afforded products formulated as 1-phenyl-3-methylbenzopyranopyrazol-5-one (yield 10percent), 1,4-dimethyl-3-phenylpyrazoloisoquinolin-5-one (yield 10percent), N-methyl-(1-phenyl-3-methyl-pyrazol-5-yl)-2-hydroxybenzamide (yield 8percent) and 4'-hydroxy-2,3'-dimethyl-1'-phenylspiro-pyrazolin>-3-one (yield 20percent).Decomposition of the diazonium sulfate derived from N-methyl-(1,3-diphenyl-pyrazol-5-yl)-2-aminobenzamide gave products formulated as 7,9-dimethyldibenzopyrazolo-diazocin-10-(9H)one (yield 8percent), 4-methyl-1,3-diphenylpyrazoloisoquinoline-5-one (yield 7percent) and 4'-hydroxy-2-methyl-1',3'-diphenylspiropyrazolin>-3-one (yield 10percent).The spiro compounds 6a,b underwent thermal and acid-catalysed conversion into the hitherto unknown 2-benzopyranopyrazole ring system 7a,b in good yield.Analytical and spectral data are presented which supported the structures proposed.
