Thiirane

Thiirane, more commonly known as ethylene sulfide, is the cyclic chemical compound with the formula C2H4S. It is the smallest sulfur-containing heterocycle. Like many organosulfur compounds, this species has a stench. Thiirane is also used to describe any derivative of the parent ethylene sulfide.

Preparation
It is prepared by the reaction of ethylenecarbonate and KSCN. For this purpose the KSCN is first melted under vacuum to remove water.
 * KSCN + C2H4O2CO  →  KOCN  + C2H4S  +  CO2

Reactions
Ethylenesulfide adds to amines to afford 2-mercaptoethylamines, which are good chelating ligands.
 * C2H4S  +  R2NH  →  R2NCH2CH2SH