Study On Synthesis Of α-Pinene-Maleic Anhydride Adduct And Its Novel Derivatives

Firstly, 1-isopropyl-4-methyl-bicyclo [2.2.2]-oct-5-ene-2, 3-dicarboxylic anhydride (a-terpinene-maleic anhydride adduct, TMA) was prepared via isomerization of a-pinene and Diels-Alder reaction with maleic anhydride in the presence of DLB as catalyst. The main Influence factors were studied and the optimal conditions were found by orthogonal experimental design to be as follows: dosage of catalyst DLB 3.5% (based on the weight of a-pinene), reaction temperature 145°C, reaction time 1.0 h, molar ratio 1.4:1 (a-pinene: maleic anhydride). As a consequence, the yield of TMA (88.2%) was up to the level in literature. Furthermore, the reaction time (1.0h) was shortened three times and the purity (92.7%) increased by 7% at the optimal conditions compared with that in literature. Beisides, the TMA product was analyzed and characterized by IR, TLC, GC and GC-MS methods.Secondly, N-(1-isopropyl- 2-carboxyl-4-methyl-bicyclo[2.2.2]-oct-5-ene-3-carbonyl)-N'- aryl-(thio) ureas were synthesized by the reaction of TMA with substituted phenyl (thio) ureas under solvent-free condition. Meanwhile, the synthetic methods and purification means were also investigated. The four prepared novel TMA derivatives which may have potential biological activities were analyzed and characterized with TLC, IR, UV, MS, ¹H-NMR and ¹³C-NMR methods.Thirdly, di-2-ethylexyl a-pinene-maleate which may be a kind of novel plasticizer was synthesized from TMA and isooctyl alcohol using toluene-p-sulfonic acid as catalyst. The optimal conditions were obtained by using the orthogonal experimental design to be as follows: molar ratio 1:3.5 of TMA to isooctyl alcohol, reaction temperature 130°C, reaction time 180min, catalyst dosage 1.0% (based on the weight of TMA). The esterification rate amounted to 93.0% under the opimal conditions. The target product was analyzed and characterized by TLC, IR, MS and ¹H-NMR methods. Besides, di-2-ethylexyl a-pinene-maleate was also synthesized under microwave irradiation. The result showed that it was more light-coloured with the esterification rate of 91. 0%...