Diethylthiambutene

Diethylthiambutene (Thiambutene, Themalon, Diethibutin, N,N-Diethyl-1-methyl-3,3-di-2-thienylallylamine) is an opioid analgesic drug developed in the 1950s^[2] which was mainly used as an anesthetic in veterinary medicine and continues, along with the other two thiambutenes dimethylthiambutene and ethylmethylthiambutene to be used for this purpose, particularly in Japan.^[3][4] 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.

Diethylthiambutene

Clinical data
ATC code	none
Legal status
Legal status	BR: Class A1 (Narcotic drugs)[1] CA: Schedule I DE: Anlage I (Authorized scientific use only) US: Schedule I UN: Psychotropic Schedule I
Identifiers
IUPAC name N,N-diethyl-4,4-dithiophen-2-yl-but-3-en-2-amine
CAS Number	86-14-6 N
PubChem CID	6833
DrugBank	DB01533 Y
ChemSpider	6572 Y
UNII	2Z91X9052O
KEGG	D12664 Y
ChEMBL	ChEMBL2106573 N
CompTox Dashboard (EPA)	DTXSID30861666
Chemical and physical data
Formula	C16H21NS2
Molar mass	291.47 g·mol−1
3D model (JSmol)	Interactive image
Melting point	152 to 153 °C (306 to 307 °F)
SMILES CCN(CC)C(C)C=C(C1=CC=CS1)C2=CC=CS2
InChI InChI=1S/C16H21NS2/c1-4-17(5-2)13(3)12-14(15-8-6-10-18-15)16-9-7-11-19-16/h6-13H,4-5H2,1-3H3 Y Key:CBYWMRHUUVRIAF-UHFFFAOYSA-N Y
NY (what is this?)  (verify)

Synthesis

Synthesis:^[5] Japan patents:^[6]

The conjugate addition of diethylamine [109-89-7] to ethyl crotonate [623-70-1] [10544-63-5] (1) gives ethyl 3-(diethylamino)butanoate, CID:10679145 (2). Addition of two equivalents of 2-thienyllithium to the ester gives the tertiary alcohol [94094-46-9] (4'). The dehydration of this then completes the synthesis of diethylthiambutene (5').