Two interrelated research topics are presented in this thesis.
Initially the preparation of a series of ring deuterium labeled alkylpyrimidines and side chain deuterium labeled methylpyrimidines has been described. Exchange of the hydrogen atoms for deuterium atoms on the methyl groups of the 2- and 4(6)-positions of the ring was readily achieved through the use of hydrochloric acid-d. In order to replace the hydrogen atoms by deuterium atoms directly on the 2- and 4(6)-positions of the ring a catalytic deuteriumolysis of a ring chlorinated alkyIpyrimidine was required, through use of deuterium gas with palladium on charcoal as the catalyst.
From a comparison of the low resolution spectra of the isotoplcally labeled and unmodified alkylpyrimidines together with accurate mass measurements and metastable defocusing results the decomposition pathways and intermediate ion structures, consistent with this data, have been proposed.
The second portion of this thesis investigated the nucleophilic displacement of a chloro substituent upon a pyrimidine ring, with or without alkyl substituents, using the anions of either ethyl isobutyrate, diethyl malonate or methyl diethyl malonate as the nucleophiles. It was intended that these substituents introduced could be used as precursors to deuterium labeled alkyl groups through a suitable synthetic sequence.
With a monochlorinated pyrimidine displacement of a chloro substituent could only be achieved at the 2-positlon of the ring. It was also found that either a 2,4- or 4,6-dichlorInated pyrimidine In addition to a 2,4,6- trichlorinated pyrimidine were more reactive than the monochlorinated species and gave displacement of the chloro substituent on the 4(6)-position of the ring. The thermal decomposition of a di(ethoxycarbonyl)all substituent on a pyrimfdine ring through deethoxycarbonylation was however an everpresent complication.
An account was also presented of the tautomeric forms detected in some di(ethoxycarbonyl)methyl substituted pyrimidines.