Oxidation and ring cleavage reactions of 3-benzhydrylchromones. Generation of triarylmethine cations from methylidenechroman-4-ones and benzopyrano[4,3-c]pyrazoles


GABBUTT C. D. , HARGROVE T. F. L. , HERON B. M. , JONES D., POYNER C., Yildiz E. , ...Daha Fazla

TETRAHEDRON, cilt.62, ss.10945-10953, 2006 (SCI İndekslerine Giren Dergi) identifier identifier

  • Cilt numarası: 62 Konu: 47
  • Basım Tarihi: 2006
  • Doi Numarası: 10.1016/j.tet.2006.08.090
  • Dergi Adı: TETRAHEDRON
  • Sayfa Sayıları: ss.10945-10953

Özet

The oxidation of 3-[bis-(diaryl)methyl]chromones 2 with p-chloranil affords novel acetals, 3-[bis-(diaryl)methylene]-2-methoxychroman-4-ones, 4 through interception of a pyrylium type intermediate. Oxidation of 3-(2-hydroxyphenyl)-4-[bis-(diaryl)methyl]pyrazoles 8, derived from 2 and hydrazines, gave 4,4-diarylbenzopyrano[4,3-c]pyrazoles 15. The electronic absorption spectra of 4 and 15 upon protonation are comparable with those of triarylmethine cationic dyes. (c) 2006 Elsevier Ltd. All rights reserved.