M+4 Stable Isotope Labeling Of Levovirin And M+7 And Carbon-14 Labeling Of Levovirin Valinate Pro-Drug

[M + 4]-labeled levovirin 5 (231 mg) was synthesized as an MS reference compound from [M + 4] triazole ester 2. [M + 7]-labeled levovirin valinate 6 (127 mg) was synthesized as a comparison MS reference compound from [M + 6] triazole ester 3. [C-14]-Levovirin 7 and [C-14]-levovirin valinate 8 were synthesized to support metabolism studies. The synthesis of 7 was accomplished in 33% overall yield (35.4mCi, 57mCi/mmol) from (BaCO3)-C-14 and 8 was synthesized in 41% yield (12.5mCi, 57mCi/mmol) from 7. An efficient metallation/carbonation reaction was developed to synthesize [C-14]-triazole ester 4. Copyright (c) 2006 John Wiley & Sons, Ltd.