C5H14N2 or cadaverine is also known as animal coniine, cadaverin, cadaverine or 1,5-pentamethylenediamine. It's a foul smelling amine derived from the amino acid lysine by decarboxylation catalysed by lysine decarboxylase. It is naturally present in decaying corpses, the roots of some plants and, strangely enough, in the flowers of the asclepiadaceae Hoodia gordonii which of course smell like garbage. More boring information follows:

Density: 0.87 
Melting point: 9 °C 
Boiling point: 178-180 °C 
Molecular weight: 102.18 g/mol
Appearance: colorless, syrupy liquid
Soluble in water, alcohol; slightly soluble in ether

NH2 --/      \-- NH2

Of course, the most interesting part is the synthesis of cadaverine. Well, unless you order it or its precursors directly from a chemistry lab, you won't be going very far. You can produce cadaverine (as well as putrescine, spermidine and histamine) by letting fish such as tuna or swordfish decay. Something more elegant would consist in soaking the flowers of Hoodia gordonii in alcohol.