Electronic Substituent Effects on the Acid-Catalyzed [4++ 2] Cycloaddition of Isopyrazoles with Cyclopentadiene and the Photochemical and Thermal Denitrogenation …

W Adam, HM Harrer, WM Nau…

Index: Adam, Waldemar; Harrer, Heinrich M.; Nau, Werner M.; Peters, Karl Journal of Organic Chemistry, 1994 , vol. 59, # 14 p. 3786 - 3797

Full Text: HTML

Citation Number: 35

Abstract

Eight symmetrically disubstituted 3, 5-diaryl-4, 4-dimethylisopyrazoles 6 with para and meta substituents (OMe, Me, H, F, C1, Br, CN, NO2) and two unsymmetrically para-substituted derivatives (OMe and NO2; Me and C02Me) were synthesized from the corresponding 1, 3- diaryl-2, 2-dimethyl-l, 3-propanediones 5, which in turn were readily available by 2, 2- dimethylation of the diones 4. The acid-catalyzed cycloaddition of cyclopentadiene to the ...