To a solution of ethyl1-[(cyclohexylamino)methyl]cyclopropane-1-carboxylate (Intermediate 273; 7.175 g, 34 mmol) in acetone (200 mL) was added potassium carbonate 7.05 g, 51 mmol) followed by 2,4-dichloro-5-nitropyrimidine (Aldrich; 9.235 g, 47.6 mmol). The reaction mixture was stirred at room temperature for 5 hours. A further addition of 2,4-dichloro-5-nitropyrimidine (4.62 g, 23.8 mmol) and potassium carbonate (3.5 g, 25.5 mmol) was made and the reaction stirred overnight at room temperature. The reaction mixture was then concentrated in vacuo and partitioned between EtOAc and water. The EtOAc layer was separated, dried over sodium sulphate and purified on a silica column eluting with EtOAc/isohexane 10:90, to yield the title compound as a yellow oil (12 g, 92%).
