ChemicalBook CAS DataBase List 1-bromo-4-prop-2-enyl-benzene

1-bromo-4-prop-2-enyl-benzene synthesis

15synthesis methods

Product Name:1-bromo-4-prop-2-enyl-benzene
CAS Number:2294-43-1
Molecular formula:C9H9Br
Molecular Weight:197.07

106-37-6 Synthesis

106-37-6
480 suppliers
$9.00/5g

106-95-6 Synthesis

106-95-6
427 suppliers
$10.00/5g

2294-43-1
39 suppliers
$256.00/1g

Yield:2294-43-1 97%

Reaction Conditions:

Stage #1: 1.4-dibromobenzenewith n-butyllithium;isopropylmagnesium chloride lithium chloride in tetrahydrofuran;hexane at -5; for 4.5 h;Inert atmosphere;
Stage #2: 3-bromo-1-propenewith copper (I) cyanide in tetrahydrofuran;hexane at -5 - 20; for 15.5 h;Inert atmosphere;

Steps:

4.2.1.1 1-Allyl-4-bromobenzene

General procedure: A 200mL three-neck round-bottom flask connected to a dropping funnel and dry argon flow was charged with a stir bar, 1,4-dibromobenzene (15.0g, 63.6mmol), and dry cyclopentyl methyl ether (35mL). The mixture was cooled to -5°C, and isopropylmagnesium chloride solution (2.0M in THF) (12.7mL, 25.4mmol) and n-BuLi solution (1.6M in hexane) (31.8mL, 50.9mmol) were added dropwise over a period of 30min, respectively. The reaction mixture was stirred for 4h at -5°C. Copper (I) cyanide (285mg, 3.18mmol, 5mol% Cu) was added at once, and the reaction mixture was stirred for 5min at -5°C. Allyl bromide (10.8mL, 127.7mmol) was then added dropwise over a period of 30min at -5°C. It was then allowed to reach room temperature and stirred for 15h. The precipitated magnesium salt was filtered off and the resulting organic phase was extracted with diethyl ether and washed with saturated NH₄Cl aqueous solution and brine and dried over anhydrous MgSO₄, filtered, and concentrated under reduced pressure. The resulting crude residue was purified by bulb-to-bulb distillation (150Pa, 50°C) affording title compound as a transparent colorless liquid (12.2g, 97% yield). ¹H NMR (400MHz, CDCl₃) δ 3.33 (d, J=6.8Hz, 2H), 5.03-5.09 (m, 2H), 5.87-5.97 (m, 1H), 7.05 (d, J=8.4Hz, 2H), 7.40 (t, J=8.4Hz, 2H). The same procedure was followed for the synthesis of 1-allyl-3-bromobenzene as described below.

References:

Maegawa, Yoshifumi;Waki, Minoru;Umemoto, Akinari;Shimada, Toyoshi;Inagaki, Shinji [Tetrahedron,2013,vol. 69,# 26,p. 5312 - 5318]

589-87-7 Synthesis