KolbeSchmitt Salicylic Acid Synthesis and Utilization Kevin Mc

Kolbe-Schmitt Salicylic Acid Synthesis and Utilization Kevin Mc. Govney Aurion Farhadi Nicholas Bean

Purpose: Synthesize Salicylic Acid Using the Kolbe-Schmitt Reaction • Kolbe-Schmitt Reaction: Was first successfully carried out in 1860 by a German chemist named Hermann Kolbe, by heating a mixture of phenol and sodium hydroxide in the presence of carbon dioxide at high pressure. • The product: Salicylic Acid!! A chemical which has proved to be immensely versatile and valuable. It is even listed in the WHO List of Essential Medicines. 1) History of Salicylic Acid. 2010 http: //www. salicylic. com/2010/08/history-of-salicylic-acid/ (Accessed March 2017)

Many uses of Salicylic Acid • Used in treatment products for acne, dandruff, and psoriasis • Used for removal of warts and calluses • Market for salicylic acid expected to reach $550 million by 2024 • Precursor to Aspirin 2) Salicylic Acid Market Size To Reach $547. 5 Million By 2024. Grand View Research 2016. 1 -2 http: //www. grandviewresearch. com/press-release/global-salicylic-acid-market (Accessed March 2017)

Identity, Structure, and Synthesis • IUPAC name 2 -hydroxybenzoic acid • Structure consists of a phenol group with an ortho-directed carboxylic acid group 3) WHO Model List of Essential Medicines. Who Medicines 2015. 19. 1 -51

4) J. Luo, S. Preciado, P. Xie, I. Larrosa, Carboxylation of Phenols with CO 2 at Atmospheric Pressure, Chem. Eur. J. 2016, 22, 6798. DOI: 10. 1002/chem. 201601114

IR and H-NMR of Salicylic Acid

Aspirin Synthesis from Salicylic Acid

IR and H-NMR of Aspirin

Differences in Spectra • Salicylic acid has alcohol and carboxylic acid groups, while aspirin has carboxylic acid and ester groups. • The alcohol groups typically show stretches between 3200 and 3600 ppm, while carboxylic acids will produce bends between 2500 and 3000 ppm. • For acetylsalicylic acid (Aspirin), we no longer see the strong stretch from the alcohol group, but we still see the presence of carboxylic acid. • New signal around 1750 ppm for ester in Aspirin 5) https: //webspectra. chem. ucla. edu/irtable. html

Merits and Deficiencies of High-Pressure Synthesis • Synthesis of Salicylic Acid can be done using cheap, common reagents • Does not provide noteworthy contribution to the reduction of atmospheric carbon dioxide • Strong economic incentive for capture and distribution of carbon dioxide as a reagent • Requires a facility that can carry out the synthesis under highpressure

Merits and Deficiencies of Low Pressure Synthesis • Takes place under standard atmospheric pressure with the addition of a 2, 4, 6 -trimethylphenyl • This allows salicylic acid to be synthesized without expensive lab equipment • Different and less common precursors are required using this method. • Variation in substitution of the phenol group results in differences in percent yield.

Summary • Kolbe-Schmitt reaction is a long standing central process to the synthesis of salicylic acid • Salicylic acid is a substance with many versatile industrial applications • The utilization of carbon dioxide in the Kolbe-Schmitt reaction provides economic incentive for its capture and distribution