Thionation of ω-hydroxy amides with Lawesson's reagent: Synthesis of thioenamides and sulfur-containing heterocycles
作者:Takehiko Nishio、Hiroshi Sekiguchi
DOI:10.1016/s0040-4020(99)00200-8
日期:1999.4
The thionation of omega-hydroxy amides with Lawesson's reagent [LR: 2,4-bis(p-methoxyphenyl)- 1,3,2,4-dithiaphosphetane-2,4-disulfide] is described. The treatment of 3-hydroxy amides 1 with LR exclusively gave thioenamides 2 in fair yields. The treatment of 4-hydroxy amides 5 with LR yielded sulfur-containing heterocycles such as tetrahydrothiophene-2-imines 6 and tetrahydrothiophene-2-thione 7a through cyclization of intermediates, 4-mercapto amides 8. The 5-hydroxy amides 13 also reacted with LR to afford tetrahydrothiopyrane-2-thione 14 as the the sole product. (C) 1999 Elsevier Science Ltd. All rights reserved.