A mixture of ethyl 2-(1-(benzyloxycarbonylamino)-4-((methylsulfonyloxy)methyl)cyclohexyl)-5-(methylsulfonyloxy)-1,6-dihydropyrimidine-4-carboxylate (2.25 g, 3.74 mmol) and cesium carbonate (1.22 g, 3.74 mmol) in DMF (40 mL) was heated at 60° C. for 18 h. The reaction mixture was then cooled and concentrated in vacuo. The residue was taken up in ethyl acetate (200 mL) and extracted with 0.2 M aq. NaOH (3×50 mL). The combined aqueous phase was washed with ethyl acetate (250 mL). The aqueous layer was then acidified with conc. HCl and extracted with CH2Cl2 (3×100 mL). The CH2Cl2 extracts were dried (Na2SO4), filtered and concentrated to afford the title compound as a brown solid (400 mg). 1H NMR (500 MHz, CDCl3) δ: 10.81 (s, 1H), 7.29-7.36 (m, 6H), 5.29 (s, 1H), 5.10 (s, 2H), 4.41 (q, 2H, J=7.27 Hz), 4.13 (d, 2H, J=3.66 Hz), 2.43-2.47 (m, 2H), 1.94-2.02 9 m, 2H), 1.79-1.85 (m, 2H), 1.65-1.72 (m, 2H), 1.40 (t, 3H, J=7.17). LCMS (M+H)=428.26.
