N-bromobutanimide → 7-(acetylamino)-4-bromo-9a-butyl-6-fluoro-1,2,9,9a-tetrahydro-3H-fluoren-3-one
Reaction equation
[C:1]([NH:4][C:5]1[CH:17]=[C:16]2[C:8]([C:9]3[C:14]([CH2:18][CH2:19][CH2:20][CH3:21])([CH2:15]2)[CH2:13][CH2:12][C:11](=[O:22])[CH:10]=3)=[CH:7][C:6]=1[F:23])(=[O:3])[CH3:2].[Br:24]N1C(=O)CCC1=O>C(Cl)Cl>[C:1]([NH:4][C:5]1[CH:17]=[C:16]2[C:8]([C:9]3[C:14]([CH2:18][CH2:19][CH2:20][CH3:21])([CH2:15]2)[CH2:13][CH2:12][C:11](=[O:22])[C:10]=3[Br:24])=[CH:7][C:6]=1[F:23])(=[O:3])[CH3:2]Participants
4
Procedure
The product from step 1 (1.1 g, approx. 3.5 mmol) was dissolved in anhydrous CH2Cl2 (11 mL) and the solution was purged with N2, cooled in an ice bath, and treated with N-bromosuccinimide (0.498 g, 2.8 mmol). After stirring at 0–5° C. for one hour, the reaction mixture was partitioned between water (150 mL) and EtOAc (150 mL). The organic portion was washed with aqueous 5% NaHCO3 and brine, dried over MgSO4, filtered, and evaporated under vacuum to provide crude 7-(acetylamino)-4-bromo-9a-butyl-6-fluoro-1,2,9,9a-tetrahydro-3H-fluoren-3-one (1.35 g).