Diethylthiocarbamyl chloride

Diethyl succinate, 30, 19 Diethyl ch-A4-tetrahydro-PHTHALATE, 30, 29 Diethylthiocarbamyl chloride,... 

The crude reaction product at 50° consists of a reddish yellow upper layer of diethylthiocarbamyl chloride saturated with sulfur (Note 6) and a viscous lower layer of amorphous sulfur saturated with diethylthiocarbamyl chloride. The mechanical stirrer is replaced by a 6-in. glass-helix-packed column arranged for distillation. A magnetic stirrer is used throughout the distillation. The diethylthiocarbamyl chloride is distilled under reduced pressure, b.p. 80-85°/l mm. (Notes 7 and 8), m.p. 48-51°. The yield is 71-72 g. (93-95%) (Notes 9 and 10). 

The hood serves to carry away unabsorbed chlorine and diethylthiocarbamyl chloride vapors. The fumes are irritating to the eyes, nose, and throat and may have other injurious physiological effects. 

An alternative method is to add chlorine to a solution or suspension of tetraethylthiuram disulfide in an inert liquid medium such as carbon tetrachloride. If the quantity and nature of the solvent are such as to dissolve the diethylthiocarbamyl chloride, most of the liberated sulfur can be separated mechanically and the chloride isolated by distillation after evaporation of the solvent. 

If the crude product is held at 50-55° for 6-8 hours, approximately 70% of the theoretical amount of free sulfur precipitates and may be separated by decantation and filtration. The remaining 30% of the theoretical quantity of sulfur remains in solution in the diethylthiocarbamyl chloride. 

The distillation may be carried out at higher pressures with only slightly more decomposition. At a pressure of 13-14 mm. diethylthiocarbamyl chloride distils at 117-120°. If the pot temperature is above 140° decomposition becomes appreciable, and at 160-190° a vigorous decomposition occurs, especially when a relatively large amount of sulfur is present. 

The crude diethylthiocarbamyl chloride need not be distilled if sulfur does not interfere in the reaction for which the chloride is to be used and if sulfur can be readily separated from the product. At approximately 105° all the sulfur liberated by the chlorination of tetraethylthiuram disulfide will dissolve in the diethylthiocarbamyl chloride, forming a homogeneous product which may be used on the basis of 100% conversion of the disulfide to the chloride. 

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