TY - JOUR
T1 - Comparative studies of the Pschorr reaction in the pyrazole series. Access to the new dibenzo(e,g)pyrazolo(1,5-a)(1,3)diazocine system of pharmaceutical interest
AU - Maggio, Benedetta
AU - Raffa, Demetrio
AU - Daidone, Giuseppe
AU - Plescia, Salvatore
AU - Sabatino, Maria Antonietta
AU - Raimondi, Maria Valeria
AU - Cascioferro, Stella Maria
AU - Meneghetti, Fiorella
AU - Bombieri, Gabriella
PY - 2008
Y1 - 2008
N2 - The diazonium tetrafluoroborate 11 obtained from 2-amino-N-methyl-N-(1-phenyl-3-methylpyrazol-5-yl)benzamide was transformed in dry acetonitrile via an ionic or radical pathway. Diferences were observed with respect to ionic or radical transformations in aqueous media of the analogous diazonium hydrogen sulfate 1 derived from the same amine. In acetonitrile solution, the ionic pathway was characterized by an increased yield of 1,4-dimethyl-3-phenyl-pyrazolo[3,4-c]isoquinolin-5-one 4 and by the formation of its isomer, the new derivative 7,9-dimethyldibenzo[e,g]pyrazolo[1,5-a][1,3]diazocin-10(9H)-one 12. When the reaction folowed a radical pathway, the pyrazolo[3,4-c]isoquinoline derivative 4 and N-methyl-2-(1-phenyl-3-methylpyrazol-5-yl)benzamide 17, the later due to a 1,4-pyrazolyl transfer proces, were isolated in low yields. Decomposition of the solid diazonium tetrafluoroborate at its melting point gave compounds 4, 12 and the N-(1-phenyl-3-methylpyrazol-5-yl)-2-fluorobenzamide 17. The crystal structure of compound 12 was also determined.
AB - The diazonium tetrafluoroborate 11 obtained from 2-amino-N-methyl-N-(1-phenyl-3-methylpyrazol-5-yl)benzamide was transformed in dry acetonitrile via an ionic or radical pathway. Diferences were observed with respect to ionic or radical transformations in aqueous media of the analogous diazonium hydrogen sulfate 1 derived from the same amine. In acetonitrile solution, the ionic pathway was characterized by an increased yield of 1,4-dimethyl-3-phenyl-pyrazolo[3,4-c]isoquinolin-5-one 4 and by the formation of its isomer, the new derivative 7,9-dimethyldibenzo[e,g]pyrazolo[1,5-a][1,3]diazocin-10(9H)-one 12. When the reaction folowed a radical pathway, the pyrazolo[3,4-c]isoquinoline derivative 4 and N-methyl-2-(1-phenyl-3-methylpyrazol-5-yl)benzamide 17, the later due to a 1,4-pyrazolyl transfer proces, were isolated in low yields. Decomposition of the solid diazonium tetrafluoroborate at its melting point gave compounds 4, 12 and the N-(1-phenyl-3-methylpyrazol-5-yl)-2-fluorobenzamide 17. The crystal structure of compound 12 was also determined.
KW - 1
KW - 4-c)isoquinoline
KW - 4-pyrazolyl transfer
KW - Pschorr reaction
KW - X-ray structure
KW - pyrazolo(3
KW - pyrazolodibenzodiazocine
KW - 1
KW - 4-c)isoquinoline
KW - 4-pyrazolyl transfer
KW - Pschorr reaction
KW - X-ray structure
KW - pyrazolo(3
KW - pyrazolodibenzodiazocine
UR - http://hdl.handle.net/10447/39022
UR - http://www.arkat-usa.org/get-file/27068/
M3 - Article
VL - 2008
SP - 130
EP - 143
JO - Arkivoc
JF - Arkivoc
SN - 1551-7004
ER -