5-[(2-Hydroxyethyl)amino]-o-cresol

Chemical Properties

Light brown powder

Uses

5-[(2-Hydroxyethyl)amino]-o-cresol is a substance present as an aminophenol component in hair dyes (especially oxidative hair dyes) and detected accordingly[2].

Flammability and Explosibility

Not classified

Synthesis

In a 250 mL four-necked flask fitted with a thermometer and stirrer, 12.3 g (0.1 mol) of 5-amino-2-methylphenol was dissolved in 80 mL of diethylene glycol dimethyl ether and heated to 150 °C. Under slow stirring in a cold trap, 4.4 g (0.1 mol) of ethylene oxide was dissolved in 10 mL of diethylene glycol dimethyl ether and 0.3 g of NaY molecular sieve catalyst was added to a four-necked flask, followed by dropwise addition of the mixture. After the dropwise addition process lasted for 0.5 hr, the reaction was continued for 3 hr. Upon completion of the reaction, the solvent was removed by distillation under reduced pressure, dried and the residue was cooled to give 16.6 g of 5-(2-hydroxyethyl)amino-o-cresol crude product. The crude product was dissolved in 100 mL of methanol-water mixed solvent and recrystallized to give 15.7 g of refined 5-(2-hydroxyethyl)amino-o-cresol in 94.1% yield and 99.52% purity.

References

[1] Patent: CN106588678,  2017,  A. Location in patent: Paragraph 0025; 0026; 0028; 0030; 0031; 0032; 0034
[2]ZHU, W., WANG, C., YANG, J., WEI, W., SUN, Z., & ZHANG, S. (2013). Simultaneous determination of 11 aminophenols in hair dyes by high performance liquid chromatography. Chinese Journal of Chromatography, 30(9), 870–875. https://doi.org/10.3724/sp.j.1123.2012.04014