Diethylthiambutene (Thiambutene, Themalon, Diethibutin, ''N'',''N''-Diethyl-1-methyl-3,3-di-2-thienylallylamine) is an
opioid
Opioids are a class of Drug, drugs that derive from, or mimic, natural substances found in the Papaver somniferum, opium poppy plant. Opioids work on opioid receptors in the brain and other organs to produce a variety of morphine-like effects, ...
analgesic
An analgesic drug, also called simply an analgesic, antalgic, pain reliever, or painkiller, is any member of the group of drugs used for pain management. Analgesics are conceptually distinct from anesthetics, which temporarily reduce, and in s ...
drug developed in the 1950s
which was mainly used as an
anesthetic
An anesthetic (American English) or anaesthetic (British English; see spelling differences) is a drug used to induce anesthesia — in other words, to result in a temporary loss of sensation or awareness. They may be divided into t ...
in
veterinary
Veterinary medicine is the branch of medicine that deals with the prevention, management, diagnosis, and treatment of disease, disorder, and injury in non-human animals. The scope of veterinary medicine is wide, covering all animal species, both ...
medicine and continues, along with the other two thiambutenes
dimethylthiambutene and
ethylmethylthiambutene to be used for this purpose, particularly in Japan.
It is now under international control under Schedule I of the UN Single Convention On Narcotic Drugs 1961, presumably due to high abuse potential, although little more information is available. It is listed under Schedule I of the US Controlled Substances Act as a Narcotic and has an ACSCN of 9616 with zero annual manufacturing quota as of 2013.
Synthesis

The conjugate addition of diethylamine
09-89-7to ethyl crotonate
23-70-1 0544-63-5(1) gives ethyl 3-(diethylamino)butanoate
CID:10679145(2). Addition of two equivalents of 2-thienyllithium to the ester gives the tertiary alcohol
4094-46-9(4'). The dehydration of this then completes the synthesis of diethylthiambutene (5').
References
{{Opioidergics
Synthetic opioids
Thiophenes
Diethylamino compounds
Mu-opioid receptor agonists