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 Novel synthesis of p-benzoquinone ethylene acetal, published in 1975, which mentions a compound: 52287-51-1, Name is 6-Bromo-2,3-dihydrobenzo[b][1,4]dioxine, Molecular C8H7BrO2, Quality Control of 6-Bromo-2,3-dihydrobenzo[b][1,4]dioxine.
PhO(CH2)2OH (I) reacted with HgO-iodine reagent (II) in the dark to give 4-RC6H4O(CH2)2OH (III; R = I). Irradiation of III (R = I) in the presence of II gave 84% title compound (IV). In contrast, irradiation of I directly, in the presence of II, gave in addition to 34% IV, 31% III (R = I), 9-14% benzodioxins V (R = H, I), and 6% p-benzoquinone. NMR studies showed that III (R = Br, Cl) were stable to II in the dark but on irradiation gave 16% IV and 30-5% V (R = Br, Cl, resp.). The mechanism for the formation of IV involved formation of an alkoxyl radical followed by cyclization and halo-elimination.
As far as I know, this compound(52287-51-1)Quality Control of 6-Bromo-2,3-dihydrobenzo[b][1,4]dioxine can be applied in many ways, which is helpful for the development of experiments. Therefore many people are doing relevant researches.
Reference:
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics