Mephedrone

Mephedrone is one of the amphetamines which often goes by the street name "bath salts". It is also chemically similar to khat, a leaf chewed for its recreational effects in Africa. 
Although it was first synthesized in 1929, it was not widely used and fell entirely out of use. It was synthesized independently in 2003 and, because it was legal, spread as a recreational drug. It was first made illegal in Israel in 2008 and by 2011 was restricted in almost every country.
Mephedrone at Wikipedia