• Clean Technology
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• v.14 no.3
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• pp.166-170
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• 2008

In this study, imidazolium salt ionic liquid on amorphous silica was prepared and its catalytic performance in the cycloaddition of $CO_2$ with allyl glycidyl ether (AGE) to produce heterocyclic carbonate was investigated. The ionic liquid was generated on chloropropyl functionalized silica through the immobilization of imidazole. The prepared catalyst was characterized using a number of instrumental analysis including XRD, BET, $^{29}Si$ MAS-NMR and SEM. $^{29}Si$ MAS-NMR showed that the ionic liquid formed adduct with the chloropropyl groups attached to the silica surface. The immobilized ionic liquid showed very good catalytic activity for the cycloaddition of $CO_2$ with AGE, showing 55-61% of AGE conversion with over 85% of the carbonate selectivity at $80-120^{\circ}C$. Its AGE conversion and selectivity to the carbonate were even higher than the homogeneous analog, 1-n-butyl-3-methyl imidazolium bromide (BMImBr).

• Archives of Pharmacal Research
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• v.15 no.1
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• pp.87-90
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• 1992

The syntheses of novel heterocyclic base modified pyrimidine nucleosides are described. 5, 6-dimethyl-4-hydroxy-3-methoxy-1-$(\beta$-D-ribofuranosyl)2(1H)-pyridinone 7 was synthesized by condensation of silylated 5, 6-dimethyl4-hydroxy-3-methoxy-2(1H)-pyridione 7 was synthesized by condensation of silylated 5, 6-dimethyl-4-hydroxy-3-methoxy-2(1H)-pyridinone with $\beta$-D-ribofuranose-1-acetate-2, 3, 5-tribenzoate in dichloroethane in the presence of Lewis acid followed by debenzoylation. The 2, 2'-anhydro-5, 6-dimethyl-2-hydroxy-3-methoxy-1-$\beta$-D-arabinofuranosyl-4-pyridinone 8 was obtained from the reaction of the free ribonucleoside 7 and diphenyl carbonate in DMF. None of these compounds showed any significant antiviral ad antitumor activities in vitro tests.