Derivatives of 6-methylbenzo[a]pyrene enriched to 90% carbon-13 at the methyl carbon were synthesized. Reactions of the carcinogen, 6-chloromethylbenzo[a]pyrene, with nucleophiles under solvolytic conditions were studied kinetically and, using labelled 6-chloromethylbenzo[a]pyrene, the reaction products were studied by CMR. The purpose was to characterize the selectivity of the benzo[a]pyrenyl- 6-methyl carbonium ion in its reactions with some simple nucleophiles and with nucleosides and other nucleic acid components.
Although the solvolysis of 6-chloromethylbenzo[a]pyrene in aqueous/organic solution is first order, information about the course of the reaction can be obtained, under certain circumstances, from rate constants. Thus, if the rate of solvolysis is slowed down by the addition of chloride ion, it can be increased by the addition of nucleophiles which compete for the carbonium ion. By using this "inhibition of the common ion effect" method, it was determined that the selectivity of the benzo[a]pyrenyl-6-methyl carbonium ion for reaction with various nucleophiles is generally in line with, yet distinct from that of other relatively stable carbonium ions. The order of nucleophilic strength of the simple nucleophiles studied is: aniline > N3- > Cl >pyridine > n-propylamine >OH- > diethylamine > H2O. Nucleosides, nucleotides and their deoxy analogs containing adenine, guanine or cytosine were found to be nucleophilic toward the carbonium ion while those containing uracil and thymine were not.
The Los Alamos Scientific Laboratory
Level of Degree
Department of Chemistry and Chemical Biology
First Committee Member (Chair)
Guido Herman Daub
Second Committee Member
David L. Vander Jagt
Third Committee Member
William Fletcher Coleman
Fourth Committee Member
Cary Jacks Morrow
Fifth Committee Member
Royer, Robert E.. "Synthesis and Studies of a Carbon-13 Labelled Chemical Carcinogen." (1977). https://digitalrepository.unm.edu/chem_etds/162