Figure 1. Synthesis of SAR218645. SAR218645 was prepared in 47% yield via the substitution of (S)-2-toluene-4-sulfonic acid methyl-2,3-dihydro-oxazolo[3,2-a]pyrimidin-7-one (6) by 1,1-dimethyl-indan-5-ol (3).

Compounds (3) and (6) were prepared in two steps from respectively, 5-methoxy-1-indanone (1) (in 43% overall yield) and from (2S)-glycidyl tosylate (4) (in 15% overall yield).