Metallic Ca-Rh/C-methanol, a high-performing system for the hydrodechlorination/ring reduction of mono- and poly chlorinated aromatic substrates.
We investigated the reduction of some substituted mono- and poly chlorobenzenes bearing functional groups such as methyl, methoxy, hydroxyl, and amino, under mild conditions (80 degrees C and magnetic stirring, for 2 h) using a system consisting of metallic calcium and methanol (as hydrogen donor system) and 5% wt. Rh/C (as hydrodechlorination/ring reduction catalyst). Hydrodechlorination easily took place for methoxy- and alkyl-chlorobenzenes, yielding the corresponding hydrodechlorinated compounds (57-76%) and affording as secondary reaction products the ring-reduced compounds (16-43%). Treatment of hydroxy- and amino-chlorobenzenes under the same conditions, respectively, gave corresponding hydrodechlorinated compounds (over 60%) along with the ring-reduced compounds. Results show that the reaction of substituted polychlorinated benzenes needs a longer reaction time (6 h), the transformation being nevertheless complete.
Mitoma
Yoshiharu
Y
Department of Environmental Sciences, Faculty of Life and Environmental Sciences, Prefectural University of Hiroshima, 562 Nanatsuka-Cho, Shobara City, Hiroshima 727-0023, Japan. mitomay@pu.hiroshima.ac.jp
Kakeda
Mitsunori
M
Simion
Alina Marieta
AM
Egashira
Naoyoshi
N
Simion
Cristian
C
D002118:Calcium / Q000032:analysis; D002713:Chlorine / Q000032:analysis / Q000737:chemistry*; D002722:Chlorobenzenes / Q000737:chemistry; D004784:Environmental Monitoring / Q000379:methods*; D004785:Environmental Pollutants / Q000032:analysis; D006859:Hydrogen / Q000737:chemistry; D008280:Magnetics; D008670:Metals; D000432:Methanol / Q000032:analysis / Q000737:chemistry*; D008956:Models, Chemical; D013696:Temperature; D013997:Time Factors
D002722:Chlorobenzenes; D004785:Environmental Pollutants; D008670:Metals; D002713:Chlorine; D006859:Hydrogen; C031294:chlorobenzene; D002118:Calcium; D000432:Methanol