Trimethyl citrate

Description

Trimethyl citrate is an ester of citric acid. It is a kind of non-toxic plasticizer¹. Trimethyl citrate is one of the constituents of Dioscorea opposita². The IC50 value for monoamine oxidase-B of trimethyl citrate was studied. It has various applications³: it can do the main flame retardant candle flame color, its melting point and can fully meet the flammability requirements of candle products. It can be used for the synthesis of pharmaceutical and pesticide. It can act as the main raw material for the production of citric acid hydrochloride, citric acid hydrochloride as well as the synthetic hot melt adhesive. It can also be used as the methyl methacrylate polymer a blowing agent, a stabilizer acrylamide, polyamide adhesive initiators, PVC plasticizers. It can also be used as solvent for household and II cleaner, film-former⁴.

Reference

1. Huang, Li, L. I. Chun-Lian, and H. U. Qing-Guo. "Study on Catalytic Synthesis of Trimethyl Citrate by Solid Acid." Liaoning Chemical Industry (2012).
2. https://www.sigmaaldrich.com/catalog/product/aldrich/27502?lang=en&region=US
3. www.zhonglanindustry.com/product/trimethyl-citrate
4. https://www.lookchem.com/Trimethyl-citrate/

Chemical Properties

Colorless crystals. M.P. 79℃. B.P. 287℃. (decomposes). Slightly soluble in water, soluble in alcohol and oils.

Uses

Trimethyl Citrate is a reagent used in the preparation of citrate-ciprofloxacin conjugates which has antibacterial activity.

Preparation

Trimethyl citrate is produced by direct esterification of Citric acid with Methanol using the old-fashioned method with 3% sulfuric acid and reflux to complete the esterification.

General Description

Trimethyl citrate is one of the constituents of Dioscorea opposita. The IC₅₀ value for monoamine oxidase-B of trimethyl citrate was studied.

Flammability and Explosibility

Not classified

Synthesis

67-56-1

77-92-9

1587-20-8

(i) Synthesis of trimethyl citrate Citric acid (9.00 g, 46.8 mmol) was dissolved in anhydrous methanol and thionyl chloride (20.50 mL, 0.28 mol) was added slowly and dropwise at 0 °C and under nitrogen protection. The reaction mixture was stirred at 0 °C for 1 h, then warmed to room temperature and continued stirring overnight. Upon completion of the reaction, the volatile components were removed by distillation under reduced pressure. The resulting solid residue was recrystallized using a hexane/ethyl acetate solvent mixture to give 10.80 g of white crystalline trimethyl citrate in 98% yield. 1H NMR (acetone-d6, 200 MHz): δ 2.85 (dd, 4H, J1 = 15.4 Hz, J2 = 27.2 Hz); 3.60 (s, 6H); 3.72 (s, 3H); 4.50 (br.s, 1H). 13C NMR (acetone-d6): calculated value: M+ = 234.21.

References

[1] Molecules, 2006, vol. 11, # 4, p. 263 - 271
[2] Patent: WO2007/14471, 2007, A1. Location in patent: Page/Page column 30
[3] Patent: US2013/89611, 2013, A1. Location in patent: Paragraph 0133-0135
[4] Molecules, 2018, vol. 23, # 9,
[5] RSC Advances, 2014, vol. 4, # 100, p. 57297 - 57307