2933.54Subheading
Heterocyclic compounds; containing a pyrimidine ring (whether or not hydrogenated) or piperazine ring in the structure, other derivatives of malonylurea (barbituric acid) and salts thereof, n.e.c. in 2933.53
Section VI — Products of the chemical or allied industries
This is a 6-digit subheading — the most specific level of the international HS. Country tariff schedules extend it further; the US tariff lines (HTS) below refine it to 8–10 digits for duty purposes.
US tariff lines for this subheading are not in the bundled starter dataset yet — the full HTS schedule is coming soon. You can still search by code in the tariff simulator.