5391. Lawesson's Reagent

Nomenclature

CAS number: 19172-47-5
2,4-Bis(4-methoxyphenyl)-1,3,2,4-dithiadiphosphetane 2,4-disulfide; anisyldithiophosphinic anhydride.
C14H14O2P2S4; mol wt 404.47.
C 41.57%, H 3.49%, O 7.91%, P 15.32%, S 31.71%.

Description and references

Thionating agent for conversion of carbonyls to thiocarbonyls. Prepn: H. Z. Lecher et al., J. Am. Chem. Soc. 78, 5018 (1956); and delineation of use: B. S. Pedersen et al., Bull. Soc. Chim. Belg. 87, 223 (1978); S. Scheibye et al., ibid. 229. Mechanistic study: T. B. Rauchfuss, G. A. Zank, Tetrahedron Lett. 27, 3445 (1986). Use in thionations: A. Z.-Q. Khan, J. Sandstrm, J. Chem. Soc. Perkin Trans. 1 1988, 2085; S. Araki et al., Bull. Chem. Soc. Jpn. 61, 2977 (1988); as reducing agent for sulfoxides: H. Bartsch, T. Erker, Tetrahedron Lett. 33, 199 (1992). Review of thionation reactions: M. P. Cava, M. I. Levinson, Tetrahedron 41, 5061-5087 (1985); of applications in organic and organometallic syntheses: M. Jesberger et al., Synthesis 2003, 1929-1958.

Chemical structure

Properties

mp 229°, should be stored under anhydrous conditions.

Use

Thiation reagent.