Sulfur Mustard

Abstract

The exact date of the first sulfur mustard synthesis is uncertain [1]. There are several reports on the formation of a chemical compound formed by the reaction of sulfur dichloride and ethylene in the early nineteenth century by the Belgian-French chemist César-Mansuète Despretz [2--5]. However, it is unclear whether Despretz realized the irritating or toxic properties of his newly discovered product [2]. The German chemist Albert Niemann reported in 1860 during experiments with ethylene and sulfur dichloride the formation of an oily liquid, ``Even traces brought into contact with the skin, while painless at first, result in a reddening of the skin after several hours, and in the following days produce blisters which fester, heal slowly and with great difficulty, and leave behind significant scarring'' [2, 6, 7]. Niemann likely suffered from sulfur mustard-induced pulmonary late effects that resulted in an early death. Almost in parallel, the British chemist Frederick Guthrie reported the same reaction [8, 9]. In 1886, the German chemist Viktor Meyer established the first reliable synthesis of pure sulfur mustard based on the chlorination of thiodiglycol, produced from chloroethanol and potassium sulfide, with phosphorus trichloride [10, 11]. This process is recognized as the ``Meyer method'' and has to be considered an important step toward the large-scale production of sulfur mustard [12]. The Levinstein process involved the reaction of ethylene and sulfur chloride and resulted in less pure products [3, 5, 13]. These impurities are responsible for the characteristic odor (garlic-, horseradish-, mustard-like) of non-distilled sulfur mustard [3, 5, 14, 15].