Mono poc-isopropyl-Tenofovir impurity

Mono poc-isopropyl-Tenofovir impurity is a structurally related API impurity derived from Tenofovir, featuring an isopropyl substitution at the cyclopropyl ring instead of the native cyclopropylmethyl group. This compound retains the core phosphonate ester functionality and terminal amino group characteristic of Tenofovir but exhibits altered steric and electronic properties due to the branched isopropyl moiety. The substitution disrupts the parent drug’s conformational flexibility, impacting its pharmacokinetic profile. This impurity arises during synthetic pathways involving cyclopropyl ring formation or phosphonate esterification. It serves as a critical HPLC reference standard for quantifying process-related impurities in Tenofovir drug substance batches.