Browsing by Author "Hung-Ming Yang"

Filter results by typing the first few letters
Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    Phase-transfer catalyzed allylation of sodium phenoxide in a solid–liquid system
    (2012-11-08) Hung-Ming Yang; Ch’un-Min Wu
    The kinetics for the O-allylation of sodium phenoxide with allyl bromide was investigated in the presence of phase-transfer catalyst in a solid–liquid system. The reaction was carried out in a stirred batch reactor under very mild operating conditions. The role of phase-transfer catalytic intermediate in the solid–liquid system was explored. Effects of various operating variables were performed. When the degree of agitation exceeded 200 rpm, the mass transfer resistance at the solid–liquid interface can be ignored. A kinetic model was proposed for the solid–liquid etherification and the experimental data were well described by the pseudo-first-order equation. The apparent activation energy was also obtained as 60.92 kJ moly1 for tetra-n-butylammonium bromide TBAB. as the catalyst. Experimental results also show that C-alkylation of sodium phenoxide with allyl bromide would not occur under the appropriate phase-transfer conditions. q2000 Elsevier Science B.V. All rights reserved.
  • Thumbnail Image
    Item
    Phase-transfer catalyzed allylation of sodium phenoxide in a solid–liquid system
    (2012-11-21) Hung-Ming Yang; Ch’un-Min Wu
    The kinetics for the O-allylation of sodium phenoxide with allyl bromide was investigated in the presence of phase-transfer catalyst in a solid–liquid system. The reaction was carried out in a stirred batch reactor under very mild operating conditions. The role of phase-transfer catalytic intermediate in the solid–liquid system was explored. Effects of various operating variables were performed. When the degree of agitation exceeded 200 rpm, the mass transfer resistance at the solid–liquid interface can be ignored. A kinetic model was proposed for the solid–liquid etherification and the experimental data were well described by the pseudo-first-order equation. The apparent activation energy was also obtained as 60.92 kJ moly1 for tetra-n-butylammonium bromide TBAB. as the catalyst. Experimental results also show that C-alkylation of sodium phenoxide with allyl bromide would not occur under the appropriate phase-transfer conditions. q2000 Elsevier Science B.V. All rights reserved