"Methadone chemical structure"@en. . . . . "wikipedia,en,900455". . "Source: Freebase - The World's database". "bbafa1aced56c9d2b9c518fc469c0f0659aa08941cf28b525f4573b13f99253a". . . . "2545"^^. . . . "141.0"^^. "119.0"^^.