292 
CHEMISTRY: JOHNSON, HILL AND KELSEY Proc. N. A. S. 
2NH2CH2CONHC6H5 + CS2 = C6H5NH.COCH2NHCSSH.NH2CH2CO- 
NHCeHs 
VIII 
The dithiocarbamate VIII interacts smoothly with ethyl chlorformate 
to give the corresponding ester represented by formula IX. This ester 
IX is the first representative of its type to be described in the chemical 
C6H5NHCOCH2NH.CSSH.NH2CH2CONHC6H5 + CLCOOC2H5 = 
C6H5NHCOCH2NH.CSS.COOC2H5 + C6H5NH.CO.CH2NH2HCI 
IX 
literature, and is a crystalline substance melting at 100°. This ester can 
be crystallized without decomposition, but undergoes the normal decompo- 
sition, characteristic of its constitution, when heated above its melting 
point temperature. It then breaks down into carbonoxysulphide, ethyl 
alcohol and the unknown isothiocyanate III. This characteristic de- 
composition reaction is expressed as follows: 
C6H5NHCOCH2NH-C = S 
heat 
C2H5OC = O 
IX 
COS + C2H5OH + C6H5NHCOCH2NCS 
j/ ni 
CeHsN CO 
CS 
NH - CH2 
VI 
Thus far we have not succeeded in stopping our reaction at the stage 
where the isothiocyanate III is formed. To our surprise this substance 
is so unstable that the heat applied to decompose the dithiocarbamic ester 
IX is sufficient to produce immediate rearrangement of the resulting iso- 
thiocyanate III into the normal phenylthiohydantoin VI. The yield of 
this cyclic compound is excellent, and as we anticipated it proved to be 
identical with the thiohydantoin previously described in the literature.^ 
We obtained no evidence of the formation of either of the two pseudo- 
thiohydantoins IV and V which result by rearrangement of thiocyanacet- 
anilide II. In other words, our method of synthesis not only excludes the 
possibility of formation of a normal thiocyanate, but has also revealed 
