Immediate Precursor for Fentanyl Placed in Schedule II In an expedited rulemaking, the Drug Enforcement Administration designated the precursor chemical 4-anilino-N-phenethyl-4-piperidine (ANPP) as a Schedule II controlled substance (75 Fed. Reg. 37,295; June 29, 2010). The substance ANPP is an immediate precursor for the Schedule II controlled substance fentanyl and is wi... Read More