Definition
2,4,6-Triformylphloroglucinol is a highly functionalised and symmetrical building block. 2,4,6-Triformylphloroglucinol contains 3 aldehyde groups which can react with nucleophiles, such as amines or anilines, to make β-ketoenamines. When the nucleophile contains more than one amine group, microporous polymers can be formed. These microporous polymers find a wide range of applications, including carbon dioxide capture.
Synthesis
In a 50 mL xylene vial, accurately weigh 2 g of hexamethylenetetramine (urotropine) and slowly add 10 mL of fresh trifluoroacetic acid. The reaction vial needs to be cooled in an ice water bath due to the exothermic nature of the reaction which may lead to loss of trifluoroacetic acid by evaporation. Under nitrogen protection, 0.67 g of resorcinol was added to the reaction system and 50 mL of glycerol was added as solvent. Subsequently, the reaction was carried out at 120°C for 1.5 h under microwave radiation conditions. Upon completion of the reaction, the reaction mixture was cooled to room temperature and extracted by adding 30 mL of dichloromethane to isolate trifluoroacetic acid. The supernatant was subjected to a simple secondary distillation (first at 40°C and atmospheric pressure, followed by raising the temperature of the distillate to 72°C) and 7 mL of the fraction was collected. The recovered concentration of trifluoroacetic acid was measured to be 98.6% and the calculated recovery was 70% by gas chromatography analysis. The solution was filtered, the filtrate was extracted with chloroform, the mixture was treated with sulfuric acid and filtered again. The filtrate was dried under vacuum to give a light pink solid. The solid was confirmed to be 1,3,5-traldehyde mesitylene trisphenol (target product) by 1H-NMR (Figure 1) analysis in a yield of 0.085 g. The solid was analyzed by 1H-NMR (Figure 1).
References
[1] Chemistry - A European Journal, 2016, vol. 22, # 47, p. 17029 - 17036
[2] Dyes and Pigments, 2016, vol. 132, p. 291 - 305
[3] Journal of Polymer Science, Part A: Polymer Chemistry, 2018, vol. 56, # 20, p. 2344 - 2353
[4] Journal of Organic Chemistry, 2009, vol. 74, # 8, p. 3168 - 3171
[5] Journal of the American Chemical Society, 2015, vol. 137, # 45, p. 14236 - 14239
