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Isomerization of Maleic Acid to Fumaric Acid Catalyzed by Cerium(IV) and N ‐Bromo Compounds
Author(s) -
Jwo JingJer,
Chen YihHsiung,
Chang EngFen
Publication year - 1983
Publication title -
journal of the chinese chemical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.329
H-Index - 45
eISSN - 2192-6549
pISSN - 0009-4536
DOI - 10.1002/jccs.198300015
Subject(s) - chemistry , isomerization , maleic acid , aqueous solution , catalysis , sulfuric acid , yield (engineering) , hydrolysis , inorganic chemistry , cerium , photochemistry , organic chemistry , materials science , copolymer , metallurgy , polymer
Maleic acid (MA) in aqueous sulfuric acid undergoes catalytic isomerization in the presence of small amounts of Cerium(IV) ion and N ‐bromosuccinimide (NBS) or N ‐bromoacetamide (NBA). The rate of isomerization is very fast even at room temperature and the yield is quite acceptable. The rate of isomerization depends on the relative amounts of MA, Ce(IV), NBS, NBA, and H 2 SO 4 . However, maleic acid has greater effect on the final yield. Sulfuric acid exhibits more chemical effect than physical effects. The competitive redox reactions of Ce(IV), NBS, and NBA with MA limit the yield of isomerization to about 85%. In the vicinity of room temperature, a raise of five degrees in temperature nearly doubles the rate of isomerization. Acrylamide shows inhibitive effect on the isomerization. The rate of hydrolysis of NBS or NBA in aqueous acidic solution depends on the concentrations of hydrogen ion, and NBS or NBA itself. The rate of hydrolysis of NBA is much faster than that of NBS. Mechanism involving bromine atom as catalyst is proposed to explain experimental results.