- The powdered bark can also be treated with solvents, such as toluene, or amyl alcohol to extract the quinine.
- The raw materials for today's dyes are mainly aromatic hydrocarbons: benzene, toluene, naphthalene, anthracene, pyrene, and others.
- Toxic chemicals such as benzene, toluene and methyl benzene were included in the list.
- In a second method, toluene is mixed with nitric acid and oxidized to produce benzoic acid.
- In combination with nitric acid, toluene gives trinitrotoluene.