5-MAPBT (5-methylaminopropylbenzothiophene) is an empathogenic drug closely related to 5-MAPB but with the oxygen atom replaced by sulfur, changing the core ring structure to benzothiophene rather than benzofuran.[2]
^WO 2022/010937, Baggott M, "Advantageous benzothiophene compositions for mental disorders or enhancement.", published 13 January 2022, assigned to Tactogen Inc.