1. The core is a six-membered piperidine ring (a saturated ring containing five carbon atoms and one nitrogen atom). Number the ring so that the ring nitrogen is N-1, and the position opposite to N is C-4.
2. N-1 carries a chain substituent consisting of a carbonyl group linked to a two-carbon spacer terminating in a primary amino group: -C(=O)-CH2-CH2-NH2.
3. At C-4 of the piperidine ring, there is an N-methyl substituent (-N(CH3)-) that also connects directly to a six-membered aromatic diazine ring (pyrazine), in which two nitrogen atoms are positioned para to each other, with the remaining atoms being carbon. The N-methyl substituent is attached at the position adjacent to one of nitrogens of the pyrazine.
4. On the pyrazine ring, at the carbon opposite the N-methyl attachment point, there is a phenyl ring. This phenyl ring bears two substituents in a meta relationship: a hydroxyl group on one position and a pyrazole ring (a five-membered aromatic heterocycle featuring two adjacent nitrogen atoms and three carbon atoms) on the other. The pyrazole ring is connected at the position meta to the hydroxyl group and para to the attachment point of pyrazine ring. Number the pyrazole such that the nitrogen bearing hydrogen is position 1, and the other nitrogen is position 2. The phenyl ring is attached at the carbon at position 4.