| In my work, six imine compounds, [o-RiOC6H4CH=NAr] ( Ri = CH3OCH2CH2, Ar = 2,6-'Pr2C6H3, la; R, = CH3OCH2CH2, Ar = 2,4,6-Me3C6H2, lb; Ri = CH3OCH2CH2, Ar= C6H5, lc; R,= CH3, Ar = 2,6-'Pr2C6H3, Id; Ri= CH3, Ar=2,4,6-Me3C6H2, le; Ri= CH3, Ar=o-CH3OC6H4, If) were synthesized by the condensation reaction of 2-(2-methoxyethoxy) aldehyde with substituted aniline. Under nitrogen atmosphere, a series of products [oRiOCf^ClrhNHAr] (Ri = CH3OCH2CH2, Ar = 2,6-/Pr2C6H3, 2a; R. = CH3OCH2CH2, Ar = 2,4,6-Me3C6H2, 2b; Ri = CH3OCH2CH2, Ar= C6H5, 2c; R,= CH3, Ar = 2,6-'Pr2C6H3, 2d; Ri= CH3> Ai=2,4,6-Me3C6H2, 2e) were obtained by reducing with lithium aluminium hydride in ether solution at room temperature. Compounds 2g [o-RiOC6H4CH(CH3)NHAr] (Ri = CH3OCH2CH2, Ar = 2,6-'Pr2C6H3) was prepared by reacting of compound la with MeMgl in toluene refluxing condition. At nitrogen atmosphere, trimethylaluminium was added dropwise into compounds 2a or 2b under rapid stirring at 110? for 10 h. The final products dimethyl aluminum complexes 3a [o-RiOC6H4CH2N(Ar)AlMe2], (R1= CH3OCH2CH2, Ar= 2,6-'Pr2C6H3) and 3b [o-R1OC6H4CH2N(Ar)AlMe2], (R1= CH3OCH2CH2, Ar= 2,4,6-Me3C6H2) were prepared after the reaction mixtures above were degassed and recrystallized in n-hexane solution.Nuclear magnetic resonance measurements were carried out to characterize the structure of the as-prepared products. The molecular structure of compound 3a was characterized by single crystal diffraction measurement. Opening polymerization reaction of ?-caprolactone was carried out by utilizing compound 3a. All the experimental results showed that compound 3a had excellent catalytic activity. Polycaprolactone with conversion of 50% was obtained by ?-caprolactone polymerizations at 30?. Meanwhile, the catalytic activity of 1c was increased with the increase of temperature, while at 100 ?, the catalytic activity was the highest, where the conversion of ?-caprolactone was above 90% after twenty minutes. |
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