2,2',4,4'-Tetrahydroxybenzophenone

Application

2,2',4,4'-Tetrahydroxybenzophenone (BZP-2) is water-soluble and light-yellow powder (figure 1). BZP-2 is widely used in perfumes to prevent their degradation due to light. BZP-2 is a UV-absorber that helps protect against product degradation because of UV-light exposure and it is widely used in sunscreens and in cosmetics (figure 2), such as: anti-aging” creams and hair sprays and shampoos, paints and plastics. It can also mask odor associated with a formulation’s composition. In addition, the hypolipemiant drug fenofibrate is also a substituted benzophenone.

Potential Exposure & Risk

Although 2,2',4,4'-Tetrahydroxybenzophenone is used as a UV-blocker in cosmetics, plastics and automotive car products, its safety issue still should be noted. Such as workers that use BZP-2 may breathe in dust or have direct skin contact and the general population may be exposed by dermal contact with products containing this compound.
Skin allergic reaction has been reported in some people using sunscreens or cosmetics containing this compound. 2,2',4,4'-Tetrahydroxybenzophenone(BZP-2) is a member of a group of chemicals known as endocrine disruptors, which may alter the function and/or development of the reproductive system. Limited evidence indicates that exposure to benzophenone UV-absorbing chemicals, including BZP-2, is associated with an altered ratio of males to females at birth (increased females).

Chemical Properties

yellow to brown crystalline powder

Uses

2,2',4,4'-Tetrahydroxybenzophenone is a uV-absorber that helps protect against product degradation because of uV-light exposure. It can also mask odor associated with a formulation’s composition.

Uses

2,2′,4,4′-Tetrahydroxybenzophenone are benzophenone-type UV filters with known or suspected endocrine disrupting properties detected in surface waters, sunscreens, personal care products, clothing and food packaging. It is used to protect the skin and materials from the adverse effects of UV-radiation.

Uses

2,2',4,4'-Tetrahydroxybenzophenone is used as the raw material of ultraviolet absorbers in cosmetics, plastics, resins and rubber. It is used as pharmaceutical intermediates and light-sensitive materials. It is also used as pharmaceutical adjuvant.

Preparation

Obtained (small amount) by melting a fluorescin chloride/sodium hydroxide mixture in the presence of a very few water at 230–240° for 2–3 h.

Contact allergens

BZP-2 is widely used in perfumes to prevent their degradation due to light. It can cause allergic contact dermatitis.

Safety Profile

Moderately toxic by ingestion. Aneye irritant. Mutation data reported. When heated todecomposition it emits toxic fumes of NOx.

Synthesis

2 mol of resorcinol dimethyl ether is added dropwise to a mixture of 1 mol of phosgene and 1 mol of aluminum chloride, and the mixture is heated to 65-80° C at a temperature of 30-40° C in the presence of a chlorinated hydrocarbon selected from aliphatic and aromatic chlorides, such as ethylene dichloride. It is then cooled to 40° C, 2 to 3 mol of aluminum chloride are added, the mixture is heated to 60-70° C, dilute hydrochloric acid is treated with aqueous sodium hydroxide solution, and 2,2',4,4'-Tetrahydroxybenzophenone is isolated by filtration.

References

[1] Jisuk Bae . (2016). Couples’ urinary concentrations of benzophenone-type ultraviolet filters and the secondary sex ratio. Science of the Total Environment, 543, Pages 28-36. https://doi.org/10.1016/j.scitotenv.2015.11.019