In general, if the atoms that make up the ring contain heteroatoms, such rings become heterocycles, and organic compounds containing heterocycles are called heterocyclic compounds. An article called 3-Phenylazopyridines, published in 1970, which mentions a compound: 1827-27-6, Name is 5-Amino-2-fluoropyridine, Molecular C5H5FN2, Formula: C5H5FN2.
Hydrogenation of 2-substituted I (X = NO2), under CO2, in MeOH with Pd/C gave I (X = NH2) (II) (method A). II were also prepared by reduction of I (X = NO2) with Fe dust in aqueous AcOH (method B). The II prepared were (R, method of preparation, and % yield given): Me, A, 95; SMe, A, 85; F, B, 70; Cl, B, 73.5; Br, B, 81; iodo, B, 86; MeO, A/B, 90.1/80.5; and AcNH, A/B, 90/70. A mixture of PhNO and II (R = MeO) kept 20 min in 50% aqueous NaOH gave III (R = OMe) (method A). In method B the above reaction was carried out at room temperature in AcOH. Similarly prepared were 7 other III analogs.
Compounds in my other articles are similar to this one(5-Amino-2-fluoropyridine)Formula: C5H5FN2, you can compare them to see their pros and cons in some ways,such as convenient, effective and so on.