5-Chloro-2-fluorobenzyl bromide synthesis

Yield:71916-91-1 75%

Reaction Conditions:

with N-Bromosuccinimide;dibenzoyl peroxide in ethyl acetate at 20 - 80; for 3 h;

Steps:

6.A
A: 5-chloro-2-fluoro-benzylbromide5-Chloro-2-fluoro-toluene (100 g, 692 mmol) was dissolved in ethylactate (300 ml) at 20 ⁰C. To this solution N-bromosuccinimide (147.7 g, 830 mmol) and dibenzoyl peroxide (2 g, 8.25 mmol) was added. The mixture was stirred at 80 ⁰C for 3 hours.Heptane (300 ml) was added and the solution was cool to 0 °C whereupon succinimide precipitates. After filtration and washing with heptane, the residue was washed with water (1500 ml). The filtrate was concentrated in vacuo to dryness, yielding 162 grams of crude 5-chloro-2-fluoro-benzylbromide. Purification of the crude product (141 grams) was done by vacuum distillation at 99 ⁰C and 33 mbar, this 5-chloro-2-fluoro-benzylbromide (99 grams, 75 %). Purity according to GC is 87.1 % a/a.¹H-NMR (CDCI₃): 4.44 (2H, d, CH₂), 7.01 (1H, t, H3), 7.26 (1H, m, H4), 7.38 (1 H, m, H6)

References:

N.V. ORGANON WO2008/3460, 2008, A1 Location in patent:Page/Page column 23-24

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