N-bromobutanimide → 2-Bromo-5-chlorobenzyl bromide

Temperatur

80 °C

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 imidodicarbonate (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).

1. filtrationfiltered
2. custompurified by flash chromatography

ORD-Eintrag

ord-09a7ea4708b443a9a3943e39f30e2221

Quelldatensatz

uspto-grants-2012_08

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US08252830B2