82737-61-9

2,4-BIS(METHYLTHIO)-1,3,2,4-DITHIADIPHOSPHETANE-2,4-DISULFIDE (Davy's reagent) is reagent for the conversion of carboxylic acids into dithioesters and carbonyl groups into thiocarbonyl groups.

2,4-BIS(METHYLTHIO)-1,3,2,4-DITHIADIPHOSPHETANE-2,4-DISULFIDE should be stored in the cold with exclusion of moisture. It is very toxic and must be handled under a hood or in glove-boxes due to its intolerable odor and the hazardous  methanethiol which is easily liberated with moisture.

It crystallises from *C6H6 in yellow plates or from hot trichlorobenzene. The low melting point reported in the literature (112o with gradual softening at 68-102o) has been attributed to the presence of elemental sulfur in the crystals. It has a foul odour and is a suspected carcinogen. [Yousif et al. Tetrahedron 40 2663 1984, Scott et al. J Org Chem 22 789 1957.]