868392-50-1Relevant articles and documents
Nonclassical Pschorr and Sandmeyer reactions in pyrazole series
Maggio, Benedetta,Daidone, Giuseppe,Raffa, Demetrio,Plescia, Salvatore,Bombieri, Gabriella,Meneghetti, Fiorella
, p. 2272 - 2281 (2007/10/03)
The diazonium salt derived from 4-amino-N,1,3-trimethyl-N-(3-methyl-1- phenyl-1H-pyrazol-5-yl)-1H-pyrazole-5-carboxamide (14) was reacted with a mixture of CuSO4 and NaCl, with ascorbic acid as an initiator to afford the planar derivative 4,6-dihydro-1,4,6,8-tetramethyl-3- phenyldipyrazolo[3,4-b:4′,3′-d]pyridin-5(3H)-one (16) and its unexpected isomer 4,6-dihydro-3,4,6,8-tetramethyl-1-phenyldipyrazolo[4,3-b: 4′,3′-d]pyridin-5(1H)-one (17), as well as the epimers (3S,4S)- (or (3S,4R)-) and (3S,4S)- (or (3S,4S)-) 4-chloro-2,4-dihydro-1′,3′,5, 5′-tetramethyl-2-phenylspiro[pyrazole-3,4′(1′H)-pyrrolo[3,4-c] pyrazol]-6′(5′H)-one (18a and b, respectively). Epimers 18a and b were converted under basic conditions to 4′-chloro-N,1,3,3′- tetramethyl-1′-phenyl-[4,5′-bi-1H-pyrazole]-5-carboxamide (19). The structures of isomers 16 and 17 determined by single-crystal X-ray analysis are also reported. Linear dichroism (LD) measurements for the above isomers suggest that 17 intercalates into DNA, and 17 exhibited antiproliferation activity against human NCI-H460 pulmonary carcinoma cells.
