[H-].[Na+].[CH3:3][CH2:4][C:5](=[O:11])[CH2:6][C:7](=[O:10])[CH2:8][CH3:9].[I-].[Na+].[C:14]([C:16]1[CH:23]=[CH:22][C:19]([CH2:20]Br)=[CH:18][CH:17]=1)#[N:15]>CC(=O)CC.C(OCC)C>[O:10]=[C:7]([CH2:8][CH3:9])[CH:6]([C:5](=[O:11])[CH2:4][CH3:3])[CH2:20][C:19]1[CH:22]=[CH:23][C:16]([C:14]#[N:15])=[CH:17][CH:18]=1
Sodium hydride (60% dispersion in oil, 3.43 g, 86 mmol) was added to a solution of 3,5-heptanedione (10 g, 78 mmol), in 2-butanone (200 ml), under nitrogen. A slight exotherm was observed during gas evolution. Sodium iodide (11.7 g, 78 mmol) was then added, followed by 4-cyanobenzyl bromide (15.29 g, 78 mmol) in 2-butanone (20 ml) and a precipitate was formed. The reaction mixture was heated at reflux for 16 hours. It was then filtered to remove the precipitate and concentrated under reduced pressure. The residue was stirred in dichloromethane (100 ml) and solid sodium bromide was removed by filtration. The dichloromethane filtrate was then washed with water (100 ml) and brine (100 ml). The organic layer was collected, dried over magnesium sulphate and concentrated under reduced pressure to give an orange solid. This was slurried in diethyl ether and filtered off to provide the title compound (11.01 g, 58%) as a pale yellow solid. 1H-NMR (400 MHz, CDCl3): δ=0.98 (t, 6H), 2.29-2.35 (m, 2H), 2.42-2.52 (m, 2H), 3.19 (d, 2H), 3.97 (t, 1H), 7.25 (d, 2H), 7.56 (d, 2H); LRMS: APCl−: m/z 242 [M−H].
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