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Synthesis 2010(18): 3087-3090  
DOI: 10.1055/s-0030-1258154
PAPER
© Georg Thieme Verlag Stuttgart ˙ New York

Facile Conversion of Thioamides into the Corresponding Amides in the Presence of Tetrabutylammonium Bromide

Kiyofumi Inamoto*, Mitsugu Shiraishi, Kou Hiroya, Takayuki Doi*
Graduate School of Pharmaceutical Sciences, Tohoku University, 6-3, Aoba, Aramaki, Aoba-ku, Sendai, 980-8578, Japan
Fax: +81(22)7956864; e-Mail: inamoto@mail.pharm.tohoku.ac.jp; e-Mail: doi_taka@mail.pharm.tohoku.ac.jp;
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Publication History

Received 13 April 2010
Publication Date:
07 July 2010 (online)

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Abstract

Desulfurization of thioamides was accomplished using a semicatalytic amount of Bu4NBr. The corresponding amides were obtained in high yields, with good functional group compatibility.

Key words

desulfurization - thioamides - amides - tetrabutylammonium bromide - thioketones

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3

Indeed, only little is known about the functional-group compatibility of this kind of desulfurization process in previous reports.

5

MeCN and DMA had a yield-improving effect similar to DMF (75% and 73% yield of 2, respectively). Use of other solvents, such as 1,4-dioxane, toluene, and 2-BuOH resulted in lower yields.

8

Unfortunately, an aliphatic thioamide such as N-phenyl-thioacetamide did not undergo the desulfurization, the reaction of which resulted in the recovery of a large amount of the starting material.