Piperidylthiambutene (Piperidinohton) is a synthetic^[1] opioid analgesic drug from the thiambutene family, which has around the same potency as morphine.^[2][3][4] Piperidylthiambutene is structurally distinct from fentanyl, its analogues, and other synthetic opioids previously reported.^[1] If sold or obtained for the purpose of human consumption it could be considered a controlled substance analogue in some countries such as the US, Australia and New Zealand. Piperidylthiambutene has been sold as a designer drug, first appearing in late 2018.^[5][6]

The Grignard reaction between 3-Piperidinobutyric acid ethyl ester, CID:10774378 (1) and 2-Bromothiophene [1003-09-4] (2) gives 3. Dehydration in acid completes the synthesis.