Chemical & Pharmaceutical Bulletin 2006-12-01

Synthesis of heterocyclic compounds via nucleophilic aroylation catalyzed by imidazolidenyl carbene.

Yumiko Suzuki, Tomonori Toyota, Akira Miyashita, Masayuki Sato

Index: Chem. Pharm. Bull. 54(12) , 1653-8, (2006)

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Abstract

Xanthones and acridones were synthesized from 3,4-difluoronitrobenzene and 2-fluorobenzaldehydes in two or three steps. The key step was nucleophilic aroylation catalyzed by imidazolidenyl carbene. The nucleophilic aroylation of 3,4-difluoronitrobenzene afforded 2,2'-difluoro-4-nitrobenzophenones. The cyclization of the difluorobenzophenones with O-nucleophile and N-nucleophile yielded 3-nitroxanthones and 3-nitroacridones, respectively. Indazole, quinolino[2,3-b]quinoxaline, and thianaphtho[2,3-b]quinoxaline derivatives were also synthesized via nucleophilic aroylation of 2,3-dichloroquinoxaline followed by cyclization with nucleophiles.