Synthesis of 2-chlorobenzyl bromide

Preparation of 2-chlorobenzyl bromide

Preparation of 2-chlorobenzyl bromide

Preparation of 2-chlorobenzyl bromide

0.2 mole of 2-chlorotoluene (o-chlorotoluene) is dissolved in a five-fold amount of dry carbon tetrachloride and is charged into a two-necked flask with a reflux condenser and a well-clamped dropping funnel. The dropping funnel should dip into the liquid in order to limit losses of bromine. The flask is heated to the boil and for each atom of hydrogen to be replaced there is added dropwise 0.205 mole of elemental bromine (bromine should be dried by shaking with concentrated sulfuric acid). During the bromination reaction, the mixture is irradiated with a 500-watt photolamp. The rate of addition of the bromine must be adjusted in such a way that the carbon tetrachloride dripping from the reflux condenser always remains practically colourless. The monobromination reaction takes about 30 min to 2 hours.  The hydrogen bromide evolved is led through the reflux condenser, which carries a pierced stopper with a glass tube and PVC tubing, into an Erlenmeyer flask half-filled with water. The inlet tube should not dip into this but end about 1 cm over the surface of the water. At the end of the reaction, the irradiation is stopped. The cooled solution is rapidly washed with ice-water, then with ice-cold aqueous sodium bicarbonate solution, and again with ice-water, and is dried with magnesium sulfate, and the carbon tetrachloride is evaporated off in vacuo. The residue after the addition of a spatulatip of sodium bicarbonate is distilled in vacuo (b.p. 104°C/12mm) yielding 80% of 2-chlorobenzyl bromide (n20/D 1.592; b.p. 103-104 °C/10 mm).

Organicum. Practical Handbook of Organic Chemistry, by Heinz Becker, Werner Berger and Günter Domschke, Addison-Wesley Pub. Co, 172-174, (1973)

Preparation of 2-chlorobenzyl bromide

Preparation of 2-chlorobenzyl bromide

0.1 mole of dry 2-chlorotoluene is dissolved in 100 ml of carbon tetrachloride that has been dried over phosphorus pentoxide, and is treated with 0.1 mole of dry N-bromosuccinimide and 2.2 g of azo-bis-isobutyronitrile. This mixture is carefully boiled under reflux in a round-bottomed flask until the reaction begins, as shown by the evolution of heat (more vigorous boiling). Although some cooling must then be applied, care must be taken that the reaction is not stopped. The end of the reaction can be seen from the fact that the denser N-bromosuccinimide has dissolved and been converted into succinimide, which floats on the surface. To ensure completion of the reaction, the mixture is boiled another few hour (the bromination reaction may take longer!). After cooling, the succinimide is filtered off and washed with a little carbon tetrachloride, and the carbon tetrachloride is distilled off from the combined filtrates under a vacuum. The residue is allowed to crystallize in the refrigerator or in a freezing mixture, and the crystals obtained are filtered off and purified by recrystallization from ethanol. The yield of 2-chlorobenzyl bromide is 80%, b.p. 104°C/12mm; n20/D 1.592.

Organicum. Practical Handbook of Organic Chemistry, by Heinz Becker, Werner Berger and Günter Domschke, Addison-Wesley Pub. Co, 174-175, (1973)





InChI Key


Canonical SMILES


Depositor-Supplied Synonyms

2-Chlorobenzyl bromide, 611-17-6, 1-(Bromomethyl)-2-chlorobenzene, o-Chlorobenzyl bromide, alpha-Bromo-2-chlorotoluene, 2-chlorobenzylbromide, Benzene, 1-(bromomethyl)-2-chloro-, 2chlorobenzyl bromide, PURSZYWBIQIANP-UHFFFAOYSA-N, ST51039913, o-chloro-benzyl bromide, PubChem12482, ACMC-209mpa, 2 -chlorobenzyl bromide, 2-chloro benzyl bromide, AC1L1YEI, AC1Q3HJQ, 2-chlorophenylmethylbromide, UNII-CEV23H8UV4, 2-chlorophenylmethyl bromide, Benzyl bromide, 2-chloro-, SCHEMBL1821, CEV23H8UV4, CHEMWISH IC04666, KSC498A1F, 1-bromomethyl-2-chlorobenzene, 1-bromomethyl-2-chloro-benzene, 252255_ALDRICH, Toluene, alpha-bromo-o-chloro-, CTK3J8012, HSDB 2678, PURSZYWBIQIANP-UHFFFAOYSA-, MolPort-000-152-739, 1-(bromo-methyl)-2-chlorobenzene, 1-(bromomethyl)-2-chloro-benzene, ALPHA-BROMO-O-CHLOROTOLUENE, Toluene, .alpha.-bromo-o-chloro-, ZINC2034437, 1-(Bromomethyl)-2-chlorobenzene #, EINECS 210-257-2, ANW-33692, MFCD00000566, ZINC02034437, AKOS009156974, AN-6040, AS02065, CM13308, CS19190, MCULE-9653977787, RTR-021061, AJ-32990, AK-94769, BC003657, BC226691, CJ-07509, CJ-31864, KB-68536, OR004327, OR142432, SC-44567, AB0010157, DB-020920, ST2415056, TR-021061, AM20040852, FT-0611924, A24598, M-6513, W-105193, 3B3-011682, 1-(bromomethyl)-2-chloro-benzen;alpha-bromo-o-chloro-toluen;, InChI=1/C7H6BrCl/c8-5-6-3-1-2-4-7(6)9/h1-4H,5H2

Removed Synonyms

CID11905, C1443

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