2,7-Dibromo-9-fluorenone → 2-Bromo-7-(5-methylhexahydropyrrolo[3,4-c]pyrrol-2-yl)-fluoren-9-one

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

A mixture of 3-methyl-3,7-diazabicyclo[3.3.0]octane (297 mg, 2.36 mmol; see Example 54C), 2,7-dibromofluoren-9-one (680 g, 2.01 mmol; Aldrich), tris(dibenzylideneacetone)dipalladium (0) (Pd2 dba3; 37 mg, 0.040 mmol; Alfa), racemic-2,2′-bis(diphenylphosphino)-1,1′-binaphthyl (BINAP; 63 mg, 0.10 mmol; Strem) and sodium tert-butoxide (270 mg, 2.81 mmol; Acros) in 10 mL toluene was warmed to 90° C. and stirred for 16 h. The reaction mixture was cooled to ambient temperature and filtered through Celite, rinsing with CH2Cl2. After concentrating the solution under reduced pressure, the residue was purified by flash chromatography (120 g silica gel, 1-20% gradient of NH4OH-MeOH (1:10) in CH2Cl2) to give the crude product. This material was purified further by flash chromatography (40 g Analogix NH2 column, 10-100% EtOAc in hexanes) to afford the title compound as a reddish solid (335 mg, 0.875 mmol; 44% yield): 1H NMR (300 MHz, CDCl3) δ ppm 7.64 (d, J=2 Hz, 1H), 7.49 (dd, J=8, 2 Hz, 1H), 7.29 (d, J=8 Hz, 1H), 7.19 (d, J=8 Hz, 1H), 6.95 (d, J=2 Hz, 1H), 6.64 (dd, J=8, 2 Hz, 1H), 3.42-3.53 (m, 2H), 3.29 (dd, J=10, 3 Hz, 2H), 2.99-3.13 (m, 2H), 2.75-2.94 (m, 2H), 2.56 (dd, J=9, 3 Hz, 2H), 2.41 (s, 3H); MS (ESI): m/z 383 (M+1)+, 385 (M+3)+.

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