Amidation, Potassium tert-butoxide, Rapeseed oil, Ethylenediamine, Diethanolamine, Dibutylamine


Background. Alkalis and metal alkoxides are used as catalysts for the amidation of vegetable oils. However, the use of known catalysts does not always allow to soften the conditions of the processes to the required level. The use of potassium tret-butoxide as a catalyst for these reactions can serve as a solution to the problem.

Objective. Verification of the use of potassium tert-butoxide as a catalyst for the amidation reaction of vegetable oil acylglycerides.

Methods. To achieve this goal, a series of syntheses of the amidation of rapeseed oil with ethylenediamine, diethanolamine and dibutylamine in the presence of potassium tert-butylate was carried out. The dependences of the yields of the target product on the catalyst content, temperature and reaction time were studied.

Results. It is shown that with the introduction of potassium t-butoxide in the reaction mixture in amounts from 0.1 to 1 mole percent, the reaction rate increases dramatically. A further increase in the amount of catalyst even to the molar ratio of 1/1 in the same conditions increases the yields by only 20% and is not advisable. The optimal molar ratio of rapeseed oil/t-butoxide was 1/0.01. It was found that the optimal temperature for carrying out the amidation in the presence of potassium tert-butoxide is in the range of 60–90 °C, depending on the structure of the amine used. It was revealed that the reaction also takes place at room temperature, although the yields of the target products are too low. However, the use of potassium tert-butoxide allows syntheses to be carried out under conditions in which hydroxides and other metal alkoxides are not effective. It is established that the optimal time for the amidation of rapeseed oil at the revealed temperature is on average 6–8 hours, depending on the structure of the amine. With reduced in temperature, in order to obtain a satisfactory yield, the time for synthesis should be increased.

Conclusions. Studies have shown that potassium tert-butoxide exhibits a significantly greater catalytic activity in the amidation reactions of oils than other alkaline catalysts. This significantly mitigates the conditions of amidation and reduces the energy costs of the process. In addition, the data obtained make it possible to further vary the temperature and time of synthesis of vegetable oil amides, depending on the tasks.

Author Biographies

Oleg I. Safronov, V.P. Kukhar Institute of Bioorganic Chemistry and Petrochemistry of the National Academy of Sciences of Ukraine

Олег Ігорович Сафронов

Oleksii O. Papeikin, V.P. Kukhar Institute of Bioorganic Chemistry and Petrochemistry of the National Academy of Sciences of Ukraine

Олексій Олександрович Папейкін

Irina O. Venger, V.P. Kukhar Institute of Bioorganic Chemistry and Petrochemistry of the National Academy of Sciences of Ukraine

Ірина Олексіївна Венгер

Larysa Yu. Bodachivska, V.P. Kukhar Institute of Bioorganic Chemistry and Petrochemistry of the National Academy of Sciences of Ukraine

Лариса Юріївна Бодачівська


V. Koval’ov et al., “An alternative source of raw materials for surfactants”, Khimichna Promyslovist’ Ukrainy, vol. 3, no. 80, pp. 10–13, 2007.

OECD/Food and Agriculture Organization of the United Nations, Agricultural Outlook 20182027. 2018, 50 p.

M. Kjellin and I. Johansson, Surfactants from Renewable Resources. West Sussex, UK: John Wiley & Sons Ltd, 2010.

B.N. Tyutyunikov et al., Chemistry of Fats. Moscow, Russia: Kolos, 1992.

V. Paronyan, Technology of Fats and Fat Substitutes. Moscow, Russia: DeLi Print, 2006.

A. Corma et al., “Chemical routes for the transformation of biomass into chemicals”, Chem. Rev, vol. 107, pp. 2411–2502, 2007.

A.P. Melnik et al., “Surface-active mono- and diacylglycerols obtaining by amidation of linseed oil”, Eastern-European Journal of Enterprise Technologies, vol. 2, no. 62, pp. 21–24, 2013.

V.Yu. Papchenko and A.P. Mel'nik, “Investigation of the production of nitrogen, oxygen-containing fatty acid derivatives by amidation sunflower oil with diethanolamine”, Visnyk NTU KHPÍ, vol. 4, pp. 3–6, 2010.

A. Adewuyi et al., “Synthesis of alkanolamide: a nonionic surfactant from the oil of Gliricidia sepium”, J. Surfactants and Detergents, vol. 15, no. 1, pp. 89–96, 2011. doi: 10.1007/s11743-011-1285-0

I.E. Korneyeva et al., “Synthesis of fatty acid amides of sunflower oil”, Bulletin of Voronezh State University, Ser. Khimiya, Biologiya, Farmatsiya, vol. 2, pp. 39–40, 2013.

E.A. Jaffar Al-Mulla et al., “Difatty acyl urea from corn oil: Synthesis and characterization”, J. Oleo Sci., vol. 59, no. 5, pp. 157–160, 2010.

A.P. Mel’nik et al., Obtaining mono-, diacylglycerides and ethanolamides by amidation of oils. Receipt. Application. Saarbrücken: Lambert Academic Publishing, 2013.

S.H. Feairheller et al., “A novel technique for the preparation of secondary fatty amides”, J. American Oil Chemists’ Society, vol. 71, no. 8, pp. 863–866, 1994.

K. Eller et al., Ullmann's Encyclopedia of Industrial Chemistry. Wiley, 2000, pp. 648–651.

L.Yu. Bodachívs’ka, “Transamination of phosphatidic concentrate with high molecular weight primary amines”, Kataliz i Neftekhimiya, vol. 17, pp. 84–90, 2009.

G.S.Pop et al., “Disperse systems based on vegetal phosphatides”, Kataliz i Neftekhimiya, vol. 22, pp. 19-26, 2013.

G.S. Pop, “Transamidation of oils and phosphatides is a promising way of synthesis of environmentally hazardous substances of complex action”, in Proc. ХХІІ Ukr. Conf. Organic Chemistry, Uzhgorod, 2010.

T.A. Patil, “Amidation of lanolin and amidation of vegetable oils for rust preventive coatings application”, Int. J. Adv. Sci. Tech. Res., vol. 6, no. 1, pp. 504–512, 2016.

D. Caine, “Potassium tert-Butoxide”, in Encyclopedia of Reagents for Organic Synthesis. New York: John Wiley & Sons, 2006. doi: 10.1002/047084289x.rp198.pub2

K. Nakanisi, Infra-Red Spectrums and Structure of Organic Compounds. Moscow, SU: Mir, 1965.

C. Siggia and Dzh.G. Khanna, Quantitative Organic Analysis by Functional Groups. Moscow, SU: Khimiya, 1983.