While compounds 21a-c were obtained in overall yields of around 78% via a convergent synthesis based on a Buchwald-Hartwig coupling using the corresponding nitrogen function and an oxidative demethylation starting from precursor 1a, molecules 21d-e were obtained in a slightly more complex manner. Indeed, the synthesis of compound 21d required an amidification reaction between intermediate 2b (obtained as described in scheme 1) and cyclopropanecarbocylic acid in the presence of HBTU before being demethylated in a