C.-Procedure B was followed except that 14.7 g. (0.1 mole) of potassium dicyanoguanidine was used instead of the sodium dicyanamide and the filtered, hot solution immediately was acidified with 25 ml. of hydrochloric acid. The product was removed after the solution had cooled to 25°, washed with cold water, and air-dried; the yield was 11.6 g. (67%). Recrystallization from water gave rosettes of coarse, white needles, whose infrared spectrum was identical with that for 31 monohydrate made by methods A or B.

No abstract

Mustard gas made by the Levinstein process is known to contain a considerable amount of material which has a high sulfur content and which has been thought to consist of the bis(2-chloroethyl) polysulfides (1). The present work deals with the identification and a study of some properties of these substances. The problem has been attacked not only by attempts to isolate pure compounds from the high-boiling fraction obtained by the Levinstein process but also by the preparation of the polysulfides by synthetic methods. THE SYNTHESIS OF THE POLYSULFIDESThe synthesis of bis (2-chloroethyl) disulfide was carried out by converting monothioglycol to bis(2-hydroxyethyl) disulfide and treating the latter with concentrated hydrochloric acid.2 HOCH2CH2SH + H202 -» (HOCH2CH2)2S2 + 2 H20 (HOCH2CH2)2S2 + 2 HC1 -> (C1CH2CH2)2S2 + 2 H20 The procedure was essentially that of Bennett (2). The last step has been modified so as to be continuous, greatly facilitating the preparation of large amounts of material. This method is of especial value in the synthesis of vesicant compounds; for example, bis (2-chloroethyl) sulfide, 1,2-bis(2-chloroethylthio)ethane, and 2-chloroethyl 2-chloro-n-propyl sulfide have been prepared in

Since the development, during World War I, of the Levinstein process for making mustard gas many attempts have been made to follow the course of the reaction and to determine the nature of the contaminants. The research reported in this series of papers was directed to this same end. It was a cooperative effort, valuable assistance being received from many sources, Notably the Chemical Warfare Service.

Chloride 6261 higher boiling fraction, b.p. 125-131°at 7 mm., indicated that this material was s;y»-7-iodo-exo-2-norbornyl acetate which was contaminated with a small amount of a diacetoxy derivative. Further purification could not be effected by fractional distillation, but a fair separation was obtained by chromatography through a 2 X 20 cm. neutral alumina column using petroleum ether-benzene for elution.