Establishing new in-house methods to increase the range of available catalogue compounds is one of our key objectives in the Apollo Labs. We have recently worked on the selective mono-trifluoromethylation of highly volatile 1,2-diketones. Similar compounds have been made via trifluoromethylations using Ruppert’s reagent in neat conditions.
Scheme 1: The initial reaction
Focusing on 2,3-butadion we trialled literature conditions and observed a VERY lively exothermic reaction resulting in a nice black tar. As always never deterred we went on and trialled several reaction conditions (temperature, equivalents, reagents, order of addition, solvent); and in the end we developed a two step process which is safe (neglectable exotherm and moderate gas evolution) and gives reproducible yields for both steps. We have scaled the process to 150g of PC50170 and are now expanding the range to other diketones.
The TMS ether PC50974 can be purified and both items are now available from stock.
Scheme 2: The final two step process