4-(1-Phenylethyl)resorcin
[CAS# 85-27-8]

Identification

• Classification: Organic raw materials >> Alcohols, phenols, phenolic compounds and derivatives
• Name: 4-(1-Phenylethyl)resorcin
• Synonyms: 4-(1-Phenylethyl)benzene-1,3-diol; 4-(1-Phenylethyl)resorcinol; 4-(alpha-Methylbenzyl)resorcinol
• Molecular Formula: C₁₄H₁₄O₂
• Molecular Weight: 214.26
• CAS Registry Number: 85-27-8
• EC Number: 480-070-0
• SMILES: CC(C1=CC=CC=C1)C2=C(C=C(C=C2)O)O

Properties

• Solubility: 265 mg/L (25 °C water)
• Density: 1.2±0.1 g/cm³, Calc.^*
• Index of Refraction: 1.616, Calc.^*
• Melting point: 129.80 °C
• Boiling Point: 365.1±17.0 °C (760 mmHg), Calc.^*, 356.53 °C
• Flash Point: 175.2±15.5 °C, Calc.^*

^* Calculated using Advanced Chemistry Development (ACD/Labs) Software.

Safety Data

• Hazard Symbols: GHS05;GHS07;GHS09 Danger
• Risk Statements: H302-H314-H315-H318-H319-H411
• Safety Statements: P260-P264-P264+P265-P270-P273-P280-P301+P317-P301+P330+P331-P302+P352-P302+P361+P354-P304+P340-P305+P351+P338-P305+P354+P338-P316-P317-P321-P330-P332+P317-P337+P317-P362+P364-P363-P391-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Skin corrosion	Skin Corr.	1B	H314
Acute toxicity	Acute Tox.	4	H302
Chronic hazardous to the aquatic environment	Aquatic Chronic	2	H411
Eye irritation	Eye Irrit.	2	H319
Serious eye damage	Eye Dam.	1	H318
Skin irritation	Skin Irrit.	2	H315

Discovery and Applications

4-(1-Phenylethyl)resorcinol, also known as SymWhite® 377 or 4PRES, is a synthetic compound that belongs to the resorcinol derivative family. It was first synthesized and characterized in the late 20th century through organic chemistry research aimed at developing novel compounds with potential applications in the pharmaceutical, cosmetic and personal care industries. The chemical structure of 4-(1-phenylethyl)resorcin consists of a resorcin core and a para-position attached phenethyl group.

One of the main applications of 4-(1-phenylethyl)resorcinol is in skin care formulas for skin whitening and brightening. It acts as a tyrosinase inhibitor, blocking the enzyme pathway responsible for melanin production in the skin. By reducing melanin synthesis, 4-(1-phenylethyl)resorcinol helps fade hyperpigmentation, dark spots, and uneven skin tone. It is often incorporated into topical creams, serums, lotions, and masks. 4-(1-phenylethyl)resorcinol is widely used as an active ingredient in the dermatological treatment of various hyperpigmentation conditions. Its depigmenting properties make it effective in reducing dark spots, age spots and blemishes caused by excess melanin production, and can be used alone or in combination with other depigmenting agents. 4-(1-Phenylethyl)resorcinol also has antioxidant properties that help protect the skin from oxidative stress and environmental damage, thereby preventing premature aging. It scavenges free radicals, neutralizes reactive oxygen species, and strengthens the skin's natural defense mechanisms to reduce signs of aging such as fine lines, wrinkles, and sagging. 4-(1-Phenylethyl)resorcinol has antibacterial and anti-inflammatory properties and is effective in treating acne and blemishes. It helps inhibit the growth of acne-causing bacteria like Propionibacterium acnes, reduces inflammation associated with acne lesions, and promotes healing of blemish-prone skin. 4-(1-Phenylethyl)resorcinol is also used in sunscreen formulations due to its photoprotective properties. It helps absorb and disperse harmful ultraviolet (UV) radiation from the sun, thereby reducing the risk of sunburn, premature aging and skin cancer. Sunscreens containing 4-(1-phenylethyl)resorcinol as a key ingredient provide broad-spectrum protection against UVA and UVB rays.

References

2023. Cosmetovigilance for infrequent allergens in Spain using a national online registry: The example of allergic contact dermatitis caused by phenylethyl resorcinol. Contact Dermatitis, 90(2).
DOI: 10.1111/cod.14460

2020. Clinical efficacy and safety of nano‐microneedle‐assisted phenylethyl resorcinol for the treatment of infraorbital dark circles. Journal of Cosmetic Dermatology, 19(8).
DOI: 10.1111/jocd.13641

2019. Characterization and topical delivery of phenylethyl resorcinol. International Journal of Cosmetic Science, 41(5).
DOI: 10.1111/ics.12565