反应详情

KOH flakes (1.3 g, 23.2 mmol) were added at RT to a solution of 1-bromo-4-(1,4-dibromobutyl)benzene (4.08 g, 10.6 mmol) (Preparation 4) and 3-(3,5-dichlorophenyl)-1-methylimidazolidine-2,4-dione (2.5 g, 9.6 mmol, prepared according to Fujinami et al. cited above) in dry DMSO (40 ml). After 30 h at RT, the reaction mixture was poured into water and extracted with EtOAc. The organic layer was dried over Na2SO4 and concentrated to yield an orange oil (4.98 g) which was chromatographed over silica gel (DCM/pentane 50/50) to give 6-(4-bromophenyl)-3-(3,5-dichlorophenyl)-1-methyl-1,3-diazaspiro[4.4]nonane-2,4-dione (2.1 g) as a white solid having the relative stereochemistry depicted above. 1H NMR (CDCl3): 7.45 (2H, d, J=8.4 Hz), 7.25 (1H, m), 7.03 (2H, d, J=8.4 Hz), 6.65 (2H, m), 3.36 (1H, dd, J1=12.9 Hz, J2=6.2 Hz), 3.13 (3H, s), 2.4-2.65 (1H, m), 1.8-2.4 (5H, m).

1. extractionextracted with EtOAc
2. dry with materialThe organic layer was dried over Na2SO4
3. concentrationconcentrated