N-bromobutanimide → 2-Bromo-5-chlorobenzyl bromide
Reaction equation
C(OC(N([CH2:16][C:17]1[CH:22]=[C:21]([Cl:23])[CH:20]=[CH:19][C:18]=1[Br:24])C(OC(C)(C)C)=O)=O)(C)(C)C.[Br:25]C1C=CC(Cl)=CC=1C.C1C(=O)N(Br)C(=O)C1>C(Cl)(Cl)(Cl)Cl.C(OOC(=O)C1C=CC=CC=1)(=O)C1C=CC=CC=1>[Br:24][C:18]1[CH:19]=[CH:20][C:21]([Cl:23])=[CH:22][C:17]=1[CH2:16][Br:25]Participants
Conditions
- Temperature
- 80 °C
Procedure
N,N-bis(tert-butoxycarbonyl)-2-bromo-5-chlorobenzylamine: To 1-bromo-4-chloro-2-methylbenzene (3.3 g, 16.06 mmol) in CCl4 (30 mL) were added NBS (3.43 g, 19.27 mmol) and benzoyl peroxide (10 mg, 0.041 mmol). The reaction was heated 80° C. overnight, then filtered and purified by flash chromatography to give 1-bromo-2-bromomethyl-4-chloro-benzene (4.5 g). 1HNMR (400 MHz, CDCl3) δ: 4.53 (s, 2 H) 7.15 (dd, J=8.59, 2.27 Hz, 1 H), 7.40-7.47 (m, 1 H), 7.49 (d, J=8.59 Hz, 1 H). This intermediate was combined with di-tert-butyl iminodicarbonate (3.49 g, 16.06 mmol) and cesium carbonate (5.23 g, 16.06 mmol) in DMF (16 mL) and stirred overnight. The reaction was partitioned with EtOAc/water and extracted with EtOAc. The combined organic layers were washed with water and brine, dried (MgSO4), and evaporated. The resulting residue was purified by flash chromatography to give 126A (3.4 g). 1HNMR (400 MHz, CDCl3) δ: 1.43-1.51 (m, 18 H), 4.82 (s, 2 H), 7.08-7.18 (m, 1 H), 7.39-7.53 (m, 2 H).
Workup
- filtrationfiltered
- custompurified by flash chromatography
Sources & evidence
- ORD record
- ord-918e7647aade40709aebef196b8fb1e9
- Source dataset
- uspto-grants-2010_11
- Patent number
- US07842708B2
Reaction notes
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