Lipase catalysed synthesis of sebacic and phthalic esters

The enzymatic synthesis and hydrolysis of alkyl sebacates and o-, m-, p-phthalates were studied. Biosyntheses were conducted through alcoholysis of dimethyl phthalates and dimethyl sebacate with 2-ethylhexanol and 3,5,5-trimethylhexanol in a solvent-free medium, using lipases from Candida antarctica (Novozym 435), Rhizomucor miehei (Lipozyme IM) and Porcine pancreas (PPL). It was found that the synthesis and hydrolysis of sebacic acid esters were characterised by a satisfactory rate, however, by low enantioselectivity. The yield of synthesis of di-3,5,5-trimethylhexyl sebacate catalysed by Novozym 435 at 50 °C was 84%, after 20 h of reaction. The degree of conversion, 62.9% after 350 h, was obtained for alcoholysis reaction of dimethyl m-phthalate with 3,5,5-trimethylhexanol. For the enzymes used, no activity was detected at all on both the synthesis and hydrolysis of di-2-ethylhexyl o-phthalate and di-3,5,5-trimethylhexyl o-phthalate.