We begin with a three-carbon main chain.
1. At the first carbon, a piperazine ring is attached. This piperazine is a six-membered heterocycle featuring two nitrogen atoms positioned opposite each other; one of these nitrogens carries a methyl substituent, while the other is directly connected to the first carbon of the chain.
2. At the third carbon of the main chain, a positively charged nitrogen (bearing one hydrogen) is attached. This nitrogen is double-bonded to a carbon atom that also carries a hydroxyl group and an additional side chain.
3. The side chain attached to this double-bonded carbon contains a single chiral center, which is R-configured. At this chiral center, one substituent is an isopropyl group (-CH(CH3)2) and the other is a phthalimide group.
   - The phthalimide-also known as an isoindoline-1,3-dione-is a fused bicyclic system in which a benzene ring is fused to a five-membered cyclic imide.
   - The cyclic imide contains one nitrogen, serving as the point of attachment to the chiral center.
   - Two carbonyl groups (=O) are present at the 1- and 3-positions of the imide ring (i.e., one at each position adjacent to the nitrogen).