Labelled compounds of interest as antitumour agents - VII. [H-2]- and [C-14]-curcumin

Curcumin (E,E-1,7-di(4-hydroxy-3-methoxyphenyl)-3-hydroxyhepta-1,3,6-trien- 5-one) is an investigational cancer chemopreventive agent. Lithium-bromine exchange of 1-bromo-4-(1-ethoxyethyl)-3-methoxybenzene with butyl lithium, quench with (OHCNMe2)-H-2 and acidic work-up gave 4-hydroxy-3-methoxybenz-[ H-2]-aldehyde ([H-2]-vanillin) in 27% yield (based on (OHCNMe2)-H-2). Conde nsation with pentane-2,4-dione then gave E,E-1,7-di(4-hydroxy-3-methoxyphen yl)-3-hydroxy-1,7-di-[H-2]-hepta-1,3,6-trien-5-one ([H-2(2)]-curcumin). Ada ptation of the procedures and use of (OHCNMe2)-C-14 provided [C-14]-curcumi n (specific radioactivity 12.7 MBq mmol(-1)) via [C-14]-vanillin.