methoxypiperamide methoxypiperamide methoxypiperamide (also known as meop and mexp) is a psychoactive drug of the piperazine class that has been sold online as a designer drug. it is the 4-methoxy-α-keto analog of methylbenzylpiperazine. methoxypiperamidelegal statuslegal status au: s9 (prohibited substance) eu: list i (hungary) identifiers iupac name (4-methoxyphenyl)(4-methylpiperazin-1-yl)methanone cas number67023-02-3pubchem cid805654chemspider704980uniiqd2gq3vgf4chemical and physical dataformulac13h18n2o2molar mass234.299 g·mol−13d model (jsmol)interactive image smiles coc1=cc=c(c=c1)c(=o)n2ccn(cc2)c inchi inchi=1s/c13h18n2o2/c1-14-7-9-15(10-8-14)13(16)11-3-5-12(17-2)6-4-11/h3-6h,7-10h2,1-2h3key:dwpvvzzgggcrrm-uhfffaoysa-n very little data exists about the pharmacology and toxicity of methoxypiperamide; however, the us state of vermont classifies it as a hallucinogen. legal status methoxypiperamide is a controlled substance in vermont as of january 2016, and also in hungary.