A kinetic study of the base catalyzed ring opening of 9-methylcaffeine halide and its homologs

<p>This study provides information about the kinetics of the hydrolytic ring cleavage of imidazolium compounds and the catalytic effect of micelles in this ring cleavage. 9-Methylcaffeine iodide was synthesized and its base catalyzed ring cleavage was studied. The ring cleavage, via alkaline hydrolysis of the imidazole moiety, showed pseudo-first order kinetics over the pH range of 7.28 to 10.81. Activation parameters were found to be: Ea = 29.4 Kcal mole^-1, △H⁺ = 28.8 Kcal mole^-1 , and △S⁺ = 27.4 cal mole^-l deg ^-1 The kinetics were studied in the presence of micelles and no rate enhancement was observed. The mechanism for ring cleavage was also investigated. 9-Ethylcaffeine iodide was synthesized and its base catalyzed ring cleavage, at 30°C and a pH of 9.42, showed pseudo first order kinetics. 6 -3 -1 The k_obs was found to be 1. 5 x 10^-3 sec^-1. The oxidation kinetics of 8 ,8-dihydro-9-methylcaffeine to 9-methylcaffeinE:· iodide were also examined.</p>

Name thesis:degree_name

Master of Science (M.S.)

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Graduate School

Year dc:date.available

1979

Author dc:creator

• Reimer, Karl Gregory

Contributors dc:contributor

• Michael J. Minch

• Halides
• Micelles
• Methylation
• Physical Sciences and Mathematics

Licence

• http://rightsstatements.org/vocab/NKC/1.0/

Repository record dc:identifier

https://scholarlycommons.pacific.edu/uop_etds/449

OAI identifier oai:identifier

oai:scholarlycommons.pacific.edu:uop_etds-1448