Chemical Properties
White powder
Uses
Light stabilizer in polymers and resins.
Application
Bisoctrizole is a non-FDA-approved combination sunscreen, but is approved in the EU and other parts of the world as a UV filter in sunscreens, day care products, and skin-whitening products at concentrations up to 10%.
Definition
ChEBI: Bisoctrizole is a diarylmethane. It is a broad-spectrum organic UV filter that is marketed as Tinosorb M. It is a benzotriazole-based organic compound that absorbs, reflects, and scatters both UV-A and UV-B rays.
Brand name
Tinosorb M (Ciba Specialty Chemicals).
General Description
2,2′-Methylenebis[6-(2H-benzotriazol-2-yl)-4-(1,1,3,3-tetramethylbutyl)phenol] is a benzotriazole based additive that is used as an ultraviolet absorber (UVA). It reduces degradation of the polymeric material by absorbing the UV radiation and converting it to thermal heat.
Side effects
At present, Bisoctrizole has good safety, photostability and effectiveness, and rarely causes skin irritation. Severe allergic reactions are rare, which may be related to the fact that it is not significantly absorbed by the skin. If you experience symptoms such as difficulty breathing or swallowing, chest tightness, rash, swelling and urticaria, you need to seek medical attention immediately. Due to the lack of clinical studies on Bisoctrizole, long-term use and adverse reactions remain to be investigated.
Safety
Bisoctrizole appears to be relatively non-toxic and rarely causes skin irritation. As with many synthetic chemicals, whether bisoctrizole may produce low-level skin damage or systemic effects with long-term use is unclear. Considering that bisoctrizole is stable, poorly soluble, and minimally absorbed by the skin, the risks appear to be low. Still, more research on bisoctrizole safety is needed.
Synthesis
1. Synthesis procedure: In a 500 mL three-necked flask equipped with a stirrer, thermometer and distillation receiver, 323 g of ultraviolet absorber UV-329, 4 g of powdered sodium hydroxide, 128 g of bis(di-n-propylamino)methane and 15 g of tetrabutylammonium bromide were added sequentially. The reaction mixture was heated to 130°C under reduced pressure at 100 mmHg with continuous stirring. During the reaction, the resulting di-n-propylamine was collected by distillation. After the reaction was carried out for 2 h, the heating was stopped and the vacuum was released. A total of 108 g of di-n-propylamine was recovered (theoretical yield: 122 g) with 88.5% recovery and 98.6% purity.
2. Purification step: When the temperature of the reaction system was lowered to 110°C, 500 g of toluene was slowly added to dissolve all the solids. After complete dissolution, the temperature of the system was lowered to 90°C. About 40 g of 18% aqueous hydrochloric acid was added dropwise slowly and stirred until the reaction system was neutral. The reaction mixture was transferred to a beaker and the crystals were cooled and crystallized in an ice water bath for 4-5 hours. The crystals were collected by filtration and washed twice with 150 mL of deionized water and twice with 250 mL of methanol sequentially. The resulting wet product was dried at 100~110°C to obtain 266 g of ultraviolet absorber UV-360 (theoretical yield: 329 g), the product melting point was 197~198°C, the yield was 80.9% and the purity was 99.6%.
References
[1] Patent: CN106478530, 2017, A. Location in patent: Paragraph 0036-0039
[2] Patent: CN106632111, 2017, A. Location in patent: Paragraph 0033; 0034; 0035; 0036; 0037-0049; 0052; 0053
