Synthesis of carbon-14 labelled 1-[4-methyl-3-mxo-4-AZA-5α-androstane-17β-carbonyl]-1,3-diisopropylurea (turosteride), a new 5α-reductase inhibitor

Abstract

SUMMARYThe synthesis in eight steps of the title compound from the commercially available[2O-"C]pregnenolone 1 is described. The expected I-[4-methyl-3-oxo-4-aza-5a-androstane-17~-[14C]carbonyl]-1,3-diisopropylurea ([14C]FCE 26073) wasobtained with a radiochemical purity higher than 97% and a specific activity of 2.03 GBq/mmol. An overall radiochemical yield of21% was achieved from 1.

Steroids: reactions and partial synthesis

“…The 5 -reductase inhibitor, furosteride 55, has been synthesized in a labelled form from [20-14 C]-pregnenolone. 115 The preparation of some antiandrogenic C-17 spiro-2oxasteroids containing substituents on ring B, e.g. 56, has been described.…”