The properties and stability of pyrrole

- Nov 02, 2017-

1. Avoid light and air contact. Prohibited with acid chloride, acid anhydride, strong oxidants, acids together. In the light and air under the color gradually become brown, resulting in resinous material. In the presence of trace amounts of inorganic acids also resin. And intense reaction with the oxidant to prevent close to the oxidant.

Chemical properties: pyrrole compared with pyridine, alkaline very weak, in the concentrated acid does not form a stable salt and polymerization, the formation of resinous material. Pyrrole with metal sodium, potassium, solid potassium hydroxide or sodium hydroxide to produce sodium or potassium salt. Salt and the role of alkyl halide into the alkyl, continue to heat the rearrangement, the formation of α-alkyl pyrrole. Pyrrole prone to halogenation reaction, the formation of tetrahalopyrrole. Such as the formation of tetraiodopyrrole with iodine in alkaline media. Nitration, sulfonation and coupling reactions can occur at the α-position of the pyrrole. Pyrrole catalyzed hydrogenation to produce tetrahydropyrrole (pyrrolidine).

2. Toxicity: LD50 (mg / kg): rat oral 61. Health hazards: Inhalation of steam can cause anesthesia, and can cause sustained increase in body temperature. Explosion hazard: This product is flammable, irritating. Hazardous characteristics: the vapor and air can form an explosive mixture, case of fire, high heat can cause combustion explosion. With the oxidant can react. High temperature decomposition, the release of highly toxic nitrogen oxide gas. Flow too fast, easy to produce and accumulate static electricity. Easy to self-polymerization, polymerization with the temperature rise sharply. Its steam than air heavier, can spread in a lower place to a considerable distance, the case of fire will fire back to fire. In case of high heat, the container pressure increases, there is the risk of cracking and explosion.