Synthesis of Carbon ‐14 and Stable Isotope Labeled Censavudine

Censavudine is a nucleoside reverse transcriptase inhibitor (NRTI) explored clinically by Bristol Myers Squibb for the treatment of human immunodeficiency virus-1 (HIV-1). As part of the development process, a carbon-14 labeled analog was synthesized for use in a human absorption, distribution, metabolism, and excretion (ADME) study. A stable isotope labeled analog was also synthesized for use as a mass spectrum internal standard in bioanalytical assays to accurately quantify the concentration of the drug in biological samples. Carbon-14 labeled Censavudine was synthesized in ten steps in a 9% overall yield from carbon-14 labeled trimethylsilylacetylene. A total of 4.44 mCi of material was prepared with a specific activity of 0.25 μCi/mg. The radiochemical and UV purities were 99% and it met all of the specifications for use in a human clinical study. Deuterium labeled Censavudine was synthesized in two steps in a 68% overall yield from [D4]-thymine. A total of 237 mg were prepared with a UV purity of 99%.

Source: Journal of Labelled Compounds and Radiopharmaceuticals - February 2, 2022 Category: Biochemistry Authors: Richard C. Burrell, Samuel J. Bonacorsi, Adrian Ortiz, Tamas Benkovics, Zhongping Shi Tags: RESEARCH ARTICLE Source Type: research