6.Benzoquinone is a type of quinone. The chemical formula is C6H4O2. There are two types: o-benzoquinone (1,2-benzoquinone) and p-benzoquinone. P-benzoquinone is more important, and benzoquinone usually refers to p-benzoquinone. P-benzoquinone is an orange-yellow crystalline solid; melting point 115-117°C, relative density 1.318 g/cm³ (20°C), can be distilled off with water vapor; soluble in water, alcohol, and medical ether. O-benzoquinone is bright red blocky or crystalline; soluble at 60-70°C; soluble in medical ether, toluene, and benzene.

1.As a quantitative determination of coniine, pyridine, azomethine, tryptophan, and hydroquinone. Carbohydrate measurement. Dehydrogenating agent. Reducing agent. Manufacturer of dyes.

2.As a polymerization inhibitor, it is used to produce hydroquinone and dye intermediates, rubber antioxidants, acrylonitrile and butyl acrylate polymerization initiators, and isopropyl titanate, etc.

3.As a single polymerization inhibitor for butadiene, vinyl acetate, methyl methacrylate, unsaturated fatty acid resins, etc., its polymerization inhibition and heat resistance are better than those of hydroquinone. It is also an initiator for the polymerization of acrylonitrile and butadiene. It is also used as an antioxidant for natural rubber, styrene-butadiene rubber, food, and other organic compounds. It is also used as a tanning agent for leather products, developer for photography, and as a dye, pharmaceutical, and cosmetic ingredient.

4.It is a common air oxidation reagent or dehydrogenation reagent, as it can be easily restored to hydroquinone by other compounds, thereby mainly showing air oxidation specificity. Moreover, its oxidation potential determines that 1,4-benzoquinone can selectively air oxidize primary allylic alcohols in the presence of a variety of alcohol compounds, such as selectively oxidizing cinnamyl alcohol to cinnamaldehyde under the coexistence of secondary pure benzyl alcohol. In addition, using 1,4-benzoquinone as a dehydrogenation reagent and hydrated zirconium oxide as a metal catalyst can also complete the oxidation reaction of primary alcohols.

5.As an intermediate of dye, it is used to measure carbohydrates in analysis.