4'-methyl-α-pyrrolidinohexiophenone 4'-methyl-α-pyrrolidinohexiophenone 4'-methyl-α-pyrrolidinohexiophenone (mphp) is a stimulant compound which has been reported as a novel designer drug. it is closely related to pyrovalerone, being simply its chain-lengthened homologue. in the pyrrolidinophenone series, stimulant activity is maintained so long as the positions of the aryl, ketone and pyrrolidinyl groups are held constant, while the alkyl backbone can be varied anywhere between three and as many as seven carbons, with highest potency usually seen with the pentyl or isohexyl backbone, and a variety of substituents are tolerated on the aromatic ring. 4'-methyl-α-pyrrolidinohexiophenoneclinical dataother namesmphplegal statuslegal status de: npsg (industrial and scientific use only) uk: class b us: schedule i illegal in sweden identifiers iupac name (rs)-1-(4-methylphenyl)-2-(1-pyrrolidinyl)-1-hexanone cas number34138-58-4pubchem cid6423085chemspider4928584uniiy8d4922f5kchemical and physical dataformulac17h25nomolar mass259.393 g·mol−13d model (jsmol)interactive imagechiralityracemic mixture smiles c2cc(c)ccc2c(=o)c(cccc)n1cccc1 inchi inchi=1s/c17h25no/c1-3-4-7-16(18-12-5-6-13-18)17(19)15-10-8-14(2)9-11-15/h8-11,16h,3-7,12-13h2,1-2h3key:yosqvmgmenucdx-uhfffaoysa-n in 2010 a group of researchers from the institute of forensic medicine, university hospital jena, germany concluded that mphp can lead to serious poisoning with toxic liver damage and rhabdomyolysis. legality in the united states, mphp is a schedule i controlled substance. sweden's public health agency suggested to classify mphp as narcotic on june 1, 2015.