Roobios-also called African red tea; the herb is touted as a rich source of antioxidants, flavanoids, and quartering, luteolin and phenolic acids.
Current materials frequently seen in hard hats include polycarbonate, Kevlar, aluminum, phenolic, and plastic.
When heated with concentrated hydrochloric acid the amino group is replaced by the hydroxyl group and the phenolic eurhodols are produced.
With zinc dust in presence of caustic soda it yields the secondary alcohol oxanthranol, C 6 H 4: CO Choh: C 6 H 4, with tin and hydrochloric acid, the phenolic compound anthranol, C5H4: CO.
They may be prepared by the reduction of nitro compounds in alkaline solution (using zinc dust and alkali, or a solution of an alkaline stannite as a reducing agent); by oxidation of hydrazo compounds; or by the coupling of a diazotized amine and any compound of a phenolic or aminic type, provided that there is a free para position in the amine or phenol.