Introduction: MXiPr's IUPAC name doubles as a set of drawing instructions, and reading it fragment by fragment shows how the ring, the methoxy group, and the isopropylamino group fit together.
Most chemistry students meet MXiPr (CAS 2666932-55-2) as a line in a catalogue: a name, a formula, a registry number, and a crystalline solid described as ≥98.0% pure. The long name usually gets skipped, which is a shame, because 2-(3-methoxyphenyl)-2-(propan-2-ylamino)cyclohexan-1-one already describes the molecule. This walkthrough works backward from the fragments of that name to the pieces of the arylcyclohexylamine skeleton, in the same order a student would annotate a hand-drawn ring on paper.
The molecular formula is the first thing worth reading, because it sets hard limits on what the structure can be. C16H23NO2 and a molecular weight of 261.36 g/mol say the molecule contains sixteen carbon atoms, twenty-three hydrogens, one nitrogen, and two oxygens. That single nitrogen matters: with only one nitrogen available, there is exactly one nitrogen position to build around, and that is where the amine sits. The two oxygens are not identical either, and the formula already implies two different oxygen environments rather than a repeated one. The formula also fixes how much unsaturation the skeleton can carry. For C16H23NO2 the double bond equivalent works out to six: sixteen carbons, minus eleven and a half hydrogens, plus half a nitrogen, plus one. A benzene ring accounts for four of those six — one ring plus three double bonds — and a cyclohexanone accounts for the other two — one ring plus the carbonyl. Six out of six means the two rings and the ketone use up everything the formula allows, leaving no room for a second carbonyl, an extra double bond, or a third ring tucked away somewhere. Counting carbons then becomes a quick audit of the name. Six carbons sit in the cyclohexane ring, six in the benzene ring, one in the methoxy methyl group, and three in the isopropyl group, and those numbers add up to exactly sixteen. When a compound is described as an arylcyclohexylamine, this is the arithmetic behind the description: an aryl ring, a cyclohexyl ring, and an amine, plus the small substituents that complete the atom count.
The full IUPAC name is 2-(3-methoxyphenyl)-2-(propan-2-ylamino)cyclohexan-1-one, and the parent structure is handed to you in the last word. That parent is cyclohexan-1-one: a saturated six-membered ring carrying a ketone at carbon 1. Numbering starts at the carbonyl carbon and continues around the ring in whichever direction gives the substituted carbon the lower locant, which places it at carbon 2. Both large substituents attach to that same carbon, so the molecule is built as a 2,2-disubstituted cyclohexanone, with the ketone and the nitrogen separated by exactly one bond.
The first substituent, 3-methoxyphenyl, is read from the inside out. Phenyl is a benzene ring joined to the cyclohexane at its own carbon 1, and 3-methoxy places an –O–CH3 group at carbon 3 of that benzene ring. That is the meta position, one step around from the point of attachment. Position matters because the 2-, 3-, and 4- isomers are separate compounds with different physical behaviour and separate registry entries, so the number 3 carries real information rather than describing a general class. The methoxy group also supplies the second oxygen in C16H23NO2 and one of the sixteen carbons.
The second substituent, propan-2-ylamino, describes the amine end of the molecule. Propan-2-yl is a three-carbon chain attached through its middle carbon, which most chemists still call isopropyl: –CH(CH3)2. Add the nitrogen and you get –NH–CH(CH3)2, a secondary amine whose nitrogen carries one hydrogen and the three-carbon fork. That nitrogen bonds to carbon 2 of the cyclohexane ring, the carbon immediately next to the ketone, so the two pieces meet as a 2-aminocyclohexan-1-one unit. This alpha relationship between carbonyl and amine is the part of the name that maps most directly onto the arylcyclohexylamine scaffold.
Short names for these compounds are compressed assembly instructions, and 3-MeO-2'-Oxo-PCiPr reads in the same order as the structure. The 3-MeO fragment is the methoxy group at position 3 of the aryl ring. The 2'-Oxo fragment marks the carbonyl oxygen on the cyclohexane ring at position 2, and the prime keeps that ring's numbering separate from the aryl numbering, so the two number systems never collide. PCiPr covers the remainder: a phenyl–cyclohexyl amine skeleton with an isopropyl group on the nitrogen. Line the three pieces up and the methoxy group, the ketone, and the isopropylamine are all accounted for. The other published synonyms work the same way. Methoxisopropamine blends methoxy and isopropylamine into one word, while Isopropyloxetamine and Isopropyxetamine blend isopropyl with an oxetamine-style core. Each name highlights a different pair of fragments, which is exactly why names travel alongside registry numbers rather than replacing them. A name describes which pieces are present and where they sit; a CAS number such as 2666932-55-2 points to one registry entry, and identity testing confirms that a given sample matches that entry. The published record for the JXSD Fine Chemicals material supplies the IUPAC name, formula, molecular weight, and a crystalline solid appearance together, and it leaves the salt form unspecified.
Once the pieces are named, the scaffold stops being an abstract category. The formula limits the molecule to two rings and one ketone, the parent name fixes the cyclohexanone as the numbered core, the two substituent blocks fill carbon 2, and the short name compresses the same facts into a label that fits in a table. A student who can move between 2-(3-methoxyphenyl)-2-(propan-2-ylamino)cyclohexan-1-one and 3-MeO-2'-Oxo-PCiPr can already describe what MXiPr is made of. Work on MXiPr pharmacology and MXiPr toxicology builds on that map later.
A: It gives the substitution pattern in three chunks. 3-MeO places a methoxy group at carbon 3 of the aromatic ring, 2'-Oxo marks the carbonyl on the cyclohexane ring at carbon 2, and PCiPr names the phenyl–cyclohexyl amine skeleton with an isopropyl group on the nitrogen. Read together, the fragments describe the same 2-(3-methoxyphenyl)-2-(propan-2-ylamino)cyclohexan-1-one structure that the IUPAC name spells out in full, just in shorter notation.
A: The name ends in cyclohexan-1-one, which makes the six-membered ketone ring the parent structure. Carbon 1 is the carbonyl carbon, and numbering continues around the ring so the substituted carbon receives the lowest locant, which is carbon 2. Both the 3-methoxyphenyl group and the propan-2-ylamino group attach at that carbon 2, so the ring carries a ketone at C1 and two substituents at C2.
A: Names describe a structure, but different naming systems and short forms can point at the same molecule, and similar names can describe different isomers. The CAS number supplies one fixed registry reference that a catalogue entry, certificate, or laboratory record can be matched against. Pairing it with the IUPAC name, formula, and molecular weight of 261.36 g/mol gives several independent handles on the same identity, which is what makes a record checkable.
