N3-Substituted Thymidine Analogues: Radiosyntheses of N3-[4-(4-(2-[18F] fluoroethyl)phenyl)butyl]thymidine and N3-[5-(4-(2-[18F]fluoroethyl)- phenyl)pentyl]thymidine for PET

Title: N3-Substituted Thymidine Analogues: Radiosyntheses of N3-[4-(4-(2-[18F] fluoroethyl)phenyl)butyl]thymidine and N3-[5-(4-(2-[18F]fluoroethyl)- phenyl)pentyl]thymidine for PET

Volume: 2 Issue: 1

Author(s): Pradip Ghosh, Juri G. Gelovani and Mian M. Alauddin

Affiliation:

Keywords: Fluorine-18, N3-substitued thymidine, TK1, PET

Abstract: Radiosyntheses of two new N3-substituted analogues of thymidine, N3-[4-(4-(2-[18F]fluoroethyl)phenyl)butyl] thymidine ([18F]-FEPBT) and N3-[5-(4-(2-[18F]fluoroethyl)phenyl)pentyl]thymidine ([18F]-FEPPT) are reported. Synthesesof the precursor compounds, 3,5-O-bis-tetrahydropyranyl-N3-[4-(4-(2-methanesulfonyl-ethyl)phenyl)butyl]thymidine and 3,5-O-bis-tetrahydropyranyl-N3-[5-(4-(2-methanesulfonyl-ethyl)phenyl)pentyl]thymidine are described. Radiofluorination of these precursors was performed using K[18F]/kryptofix 2.2.2. in dry MeCN. Hydrolysis of the protecting groups followed by HPLC purification yielded the desired products [18F]-FEPBT and [18F]-FEPPT. The radiochemical yields of [18F]-FEPBT were 35%-48% decay corrected (d. c.) with an average of 44%; and those of [18F]-FEPPT were 32%-40% (d. c.) with an average of 37% in three runs per compound. Radiochemical purity was > 99% and specific activity was > 74 GBq/μmol at the end of synthesis. The synthesis time was 80-90 min from the end of bombardment (EOB).

Cite this article as:

Ghosh Pradip, Gelovani G. Juri and Alauddin M. Mian, N3-Substituted Thymidine Analogues: Radiosyntheses of N3-[4-(4-(2-[18F] fluoroethyl)phenyl)butyl]thymidine and N3-[5-(4-(2-[18F]fluoroethyl)- phenyl)pentyl]thymidine for PET, Current Radiopharmaceuticals 2009; 2 (1) . https://dx.doi.org/10.2174/1874471010902010002