A CONVENIENT SYNTHESIS OF 9H-THIOXANTHEN-9-ONES AND THEIR AZA-ANALOGUES

作者：Kobayashi Kazuhiro^*; Komatsu Toshihide; Nakagawa Kazuhiro; Hara Erika; Yuba Shohei

来源：Heterocycles, 2013, 87(12): 2577-2587.

DOI：10.3987/COM-13-12855

• 9H-Thioxanthen-9-one
• 5H-[1]Benzothiopyrano[2,3-b]- (and- [2,3-c])pyridin-5-one
• 10H-[1]Benzothiopyrano[3,2-c]pyridin-10-one
• Sodium Sulfide

An efficient method for the preparation of 9H-thioxanthen-9-ones and their three aza-analogues has been developed. The reaction of (2-fluorophenyl)(2-halophenyl)methanones, derived from 1-bromo-2-fluorobenzenes and 2-halobenzaldehydes by an easy two-step sequence, with Na2S center dot 9H(2)O in DMF at 60 degrees C gives 9H-thioxanthen-9-ones. This procedure can be applied to the synthesis of 5H-[1]benzothiopyrano[2,3-b] (or [2,3-c])pyridin-5-ones or 10H-[1]benzothiopyrano[3,2-c]pyridin-10-ones starting from 2-, 3- or 4-chloropyridines, respectively.

• 出版日期2013-12-1