To a solution of {[8-(cyclopropylmethyl)-1,4-dioxaspiro[4.5]dec-8-yl]methyl}amine (7 g; 31.0 mmol) and n-ethyldiisopropylamine (6.45 ml; 37.2 mmol) in DCM (60 ml) at 0° C. was added 2,4-dichlorobenzoyl chloride (4.781 ml; 34.17 mmol) dropwise and the solution stirred for 4 hours warming to ambient temperature. The reaction was partitioned between DCM (50 ml) and water (20 ml). The aqueous phase was extracted with DCM (20 ml) and the combined organics dried over MgSO4, filtered and evaporated to give a colourless oil which was used in the next step without further purification. (11.5 g) 1H NMR δ (ppm) (CDCl3): 7.67 (1H, d, J=8.3 Hz), 7.43 (1H, d, J=2.0 Hz), 7.32 (1H, dd, J=2.0, 8.4 Hz), 6.25 (1H, s), 3.93 (4H, s), 3.56 (2H, d, J=6.2 Hz), 1.67 (8H, m), 1.33 (2H, d, J=6.7 Hz), 0.75-0.65 (1H, m), 0.51-0.47 (2H, m), 0.05 (2H, q, J=5.0 Hz). MS (m/e)=398
