Thiirane, more commonly known as ethylene sulfide, is the cyclic chemical compound

Chemical compound

A chemical compound is a pure chemical substance consisting of two or more different chemical elements that can be separated into simpler substances by chemical reactions. Chemical compounds have a unique and defined chemical structure; they consist of a fixed ratio of atoms that are held together...

 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 ethylene carbonate

Ethylene carbonate

Ethylene carbonate is an ester of ethylene glycol and carbonic acid. At room temperature ethylene carbonate is a transparent crystalline solid, practically odorless and colorless, and somewhat soluble in water. In the liquid state Ethylene carbonate is an ester of ethylene glycol and carbonic...

 and KSCN

Potassium thiocyanate

Potassium thiocyanate is the chemical compound with the molecular formula KSCN. It is an important salt of the thiocyanate anion, one of the pseudohalides...

. 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