Fig. 4. Synthetic scheme for the preparation of 3-cyclopentyl-1-(3-(4-((methylamino) methyl)phenyl) tetrahydropyrimidin-1(2H)-yl)propan-1-one (3). (a) di-tert-butyl dicarbonate, NEt3, THF; 0 → 22 °C; overnight; (b) di-tert-butyl dicarbonate, NEt3, THF; 0 → 22 °C; overnight; (c) NaBH4, MeOH, 0 °C; 2 h; (d) 3-cyclopentylpropionic acid, DCM, diisopropylethylamine, COMU, 22 °C; 18 h; (e) TFA, DCM, 22 °C; 2 h; (f) Pd(OAc)2, KOtBu, 2-(di-tert-butylphosphino) biphenyl, toluene; 100 °C, 4 h; (g) TFA, DCM, 22 °C; 2 h.
