Towards the synthesis of (all-rac)-α-tocopherol from trimethylhydroquinone and isophytol at reduced pressure
Juraj Gömöry, Milan Králik a, Alexander Kaszonyi * b
Zentiva a.s., Nitrianska 100, 920 27 Hlohovec
a VUCHT j.s.c., Research Institute of Chemical Technology, Nobelova 34, 836 03 Bratislava, Slovak Republic
b Department of Organic Technology, Slovak University of Technology, Radlinského 9, 812 37 Bratislava, Slovak Republik
E-mail: * alexander.kaszonyi@stuba.sk
Abstract: The cyclocondensation of trimethylhydroquinone and isophytol to (all-rac)-α-tocopherol was studied at reduced pressure at the presence of water or (all-rac)-α-tocopherol as solvent, and ZnCl2 as catalyst. The obtained results confirm that the yield of (all-rac)-α-tocopherol can be increased at reduced pressure due to more efficient removal of reaction water, generated by the condensation reaction of isophytol (IPh) and trimethylhydroquinone (TMHQ). Auxiliary (all-rac)-α-tocopherol used as solvent makes a better reaction medium than water and the reached highest yield 89 % is comparable with result obtained at the presence of butyl acetate as solvent.
Keywords: (all-rac)-α-tocopherol, trimethylhydroquinone, isophytol, ZnCl2, catalyst
Full paper in Portable Document Format: acs_0076.pdf
Acta Chimica Slovaca, Vol. 4, No. 1, 2011, pp. 3—14