Reaction #46647

Reaction equation

(S)-1-benzyl 4-methyl 2-aminosuccinate

9-bromo-9-phenyl-9H-fluorene

Et3N

→

(S)-1-benzyl 4-methyl 2-(9-phenyl-9H-fluoren-9-ylamino)succinate

Solvents

CH2Cl2

Conditions

Workup

1. 1
   FiltrationThe mixture was filtered
2. 2
   workup.ADDITIONthe filtrate was treated with MgSO4
3. 3
   Filtrationfiltered again
4. 4
   Concentrationthe final filtrate was concentrated
5. 5
   OtherThe resulting crude material was submitted to a Biotage purification (350 g silica gel, CH2Cl2 elution)

Procedure

Pb(NO3)2 (6.06 g, 18.3 mmol) was added over 1 min to a CH2Cl2 (80 mL) solution of (S)-1-benzyl 4-methyl 2-aminosuccinate (4.50 g, 19.0 mmol), 9-bromo-9-phenyl-9H-fluorene (6.44 g, 20.0 mmol) and Et3N (3.0 mL, 21.5 mmol), and the heterogeneous mixture was stirred at ambient condition for 48 hr. The mixture was filtered and the filtrate was treated with MgSO4 and filtered again, and the final filtrate was concentrated. The resulting crude material was submitted to a Biotage purification (350 g silica gel, CH2Cl2 elution) to afford (S)-1-benzyl 4-methyl 2-(9-phenyl-9H-fluoren-9-ylamino)succinate as highly viscous colorless oil (7.93 g). 1H NMR (DMSO-d6, δ=2.5 ppm, 400 MHz): δ 7.82 (m, 2H), 7.39-7.13 (m, 16H), 4.71 (d, J=12.4, 1H), 4.51 (d, J=12.6, 1H), 3.78 (d, J=9.1, NH), 3.50 (s, 3H), 2.99 (m, 1H), 2.50-2.41 (m, 2H, partially overlapped with solvent). LC (Cond. 1): RT=2.16 min; LC/MS: Anal. Calcd. for [M+H]+ C31H28NO4: 478.20. found 478.19.

Source