Title: Ethylmethylthiambutene
CAS Registry Number: 441-61-2
CAS Name: N-Ethyl-N-methyl-4,4-di-2-thienyl-3-buten-2-amine
Additional Names: N-ethyl-N,1-dimethyl-3,3-di-2-thienyl-2-propenamine; N-ethyl-N,1-dimethyl-3,3-di-2-thienylallylamine; 3-ethylmethylamino-1,1-di(2¢-thienyl)but-1-ene; ethylmethiambutene
Manufacturers' Codes: 1C50; NIH-5145
Trademarks: Emethibutin
Molecular Formula: C15H19NS2
Molecular Weight: 277.45
Percent Composition: C 64.93%, H 6.90%, N 5.05%, S 23.11%
Literature References: Prepn: Adamson, US 2561899 (1951 to Burroughs Wellcome). Toxicology: N. B. Eddy, D. Leimbach, J. Pharmacol. Exp. Ther. 107, 385 (1953).
Properties: bp0.01 110-113°; bp18 75-76°.
Boiling point: bp0.01 110-113°; bp18 75-76°
Derivative Type: Hydrochloride
Molecular Formula: C15H19NS2.HCl
Molecular Weight: 313.91
Percent Composition: C 57.39%, H 6.42%, N 4.46%, S 20.43%, Cl 11.29%
Properties: Crystals, mp 137-138°. LD50 in mice (mg/kg): 192 orally; 88 s.c. (Eddy, Leimbach).
Melting point: mp 137-138°
Toxicity data: LD50 in mice (mg/kg): 192 orally; 88 s.c. (Eddy, Leimbach)
NOTE: This is a controlled substance (opiate): 21 CFR, 1308.11.
Therap-Cat: Analgesic (narcotic).
Keywords: Analgesic (Narcotic).
Ethylmorphine Ethylnorepinephrine Ethylparaben Ethylstibamine Ethynodiol

Ethylmethylthiambutene structure.svg
Systematic (IUPAC) name
Clinical data
Legal status Schedule I (US)
CAS number 441-61-2
ATC code None
PubChem CID 46424
DrugBank DB01468
ChemSpider 42256 YesY
UNII 722BFZ899Q YesY
Chemical data
Formula C15H19NS2 
Mol. mass 277.45 g/mol
 YesY (what is this?)  (verify)

Ethylmethylthiambutene (N-ethyl-N-methyl-1-methyl-3,3-di-2-thienylallylamine, Emethibutin) is an opioid analgesic drug from the thiambutene family, around 1.3x the potency of morphine.[1][2][3] It is under international control under Schedule I of the UN Single Convention On Narcotic Drugs 1961, presumably due to high abuse potential.