Abstract In support of a research program aimed at discovering purine-related anticancer drug candidates, a method for the 14 C-labeling of pyrazolopyrimidines utilizing the readily available labeled starting material, sodium [14 C] formate, has been developed with a good overall yield. This new method was proven to be general in the preparation of other related [4.3. 0] heterocycles containing N, O, and S atoms. A concise synthesis of a model ...
![5-methyl-6-phenylthieno[2,3-d]pyrimidin-4-ol Structure](https://image.chemsrc.com/caspic/475/306934-76-9.png)
![7-methyl-9-oxa-2,4,8-triazabicyclo[4.3.0]nona-1,3,6-trien-5-one Structure](https://image.chemsrc.com/caspic/208/68571-74-4.png)