Heterocyclic compound is a major class of organic chemical compounds characterized by some or all of the atoms in their molecules are joined in rings containing atleast one atom of an element other than carbon.

CAS Number
15307-86-5
Alternate CAS Number
15307-79-6 (Na salt); 15307-81-0 (K salt)
CAS Number
2349-67-9
Alternate CAS Number
3234-61-5(Cu Salt)