Syntheses of colchicine and isocolchicine labelled with carbon-11 or carbon-13

Article abstract of DOI:10.1002/jlcr.2580360603

The syntheses of isotopically labelled (-)-10-[¹¹C/¹³C]-colchicine and (-)-9-[¹¹C/¹³C]-isocolchicine have been achieved from the reaction of (-)desmethylcolchicine with [¹¹C/¹³C]-iodomethane. The radiolabelled compounds, (-)-10-[¹¹C]-colchicine (¹¹C-n-colchicine) and (-)-9-[¹¹C]-isocolchicine (¹¹C-i-colchicine), were isolated by reversed phase HPLC. The total synthesis time was approximately 60 minutes for both radiolabelled compounds with an average specific activity of 240 mCi/μmol calculated to EOB. Utilizing a similar synthetic strategy, we also report the synthesis of milligram quantities of the carbon-13 enriched compounds and the magnetic resonance signal assignment for (-)-9-[¹³C] isocolchicine.