Crystallographic characterization of three cathinone hydrochlorides new on the NPS market: 1-(4-methylphenyl)-2-(pyrrolidin-1-yl)hexan-1-one (4-MPHP), 4-methyl-1-phenyl-2-(pyrrolidin-1-yl)pentan-1-one (α-PiHP) and 2-(methylamino)-1-(4-methylphenyl)pentan-1-one (4-MPD).

Cathinones belong to a group of compounds of great interest in the new psychoactive substances (NPS) market. Constant changes to the chemical structure made by the producers of these compounds require a quick reaction from analytical laboratories in ascertaining their characteristics. In this article, three cathinone derivatives were characterized by X-ray crystallography. The investigated compounds were confirmed as: 1-[1-(4-methylphenyl)-1-oxohexan-2-yl]pyrrolidin-1-ium chloride (1, CHNO·Cl, the hydrochloride of 4-MPHP), 1-(4-methyl-1-oxo-1-phenylpentan-2-yl)pyrrolidin-1-ium chloride (2; CHNO·Cl, the hydrochloride of α-PiHP) and methyl[1-(4-methylphenyl)-1-oxopentan-2-yl]azanium chloride (3; CHNO·Cl, the hydrochloride of 4-MPD). All the salts crystallize in a monoclinic space group: 1 and 2 in P2/c, and 3 in P2/n. To the best of our knowledge, this study provides the first detailed and comprehensive crystallographic data on salts 1-3.