Synthesis of isobutyl bromide

Preparation of isobutyl bromide (1-bromo-2-methylpropane)

With cooling, 1 mole of the isobutyl alcohol is treated first with 0.5 mole of concentrated sulfuric acid and then with 1.25 mole of hydrogen bromide (in the form of the 48%, constant-boiling, acid), and the obtained mixture is boiled and volatile isobutyl bromide is distilled out from the reaction mixture directly (20-cm Vigreux column, vertical condenser, rate of distillation 2 to 3 drops per second). The obtained crude isobutyl bromide is twice shaken carefully with about one-fifth of its volume of cold concentrated sulfuric acid or the same volume of concentrated hydrochloric acid in the separating funnel to dissolve the ether produced as a by-product. Then crude isobutyl bromide is washed with water then it is freed from acid with sodium bicarbonate solution, washed again with water, dried over calcium chloride, and distilled through a 20-cm Vigreux column. The yield of isobutyl bromide is 80%, n20/D 1.435; b.p. 90-92 °C; d=1.26 g/mL at 20 °C.

Organicum. Practical Handbook of Organic Chemistry, by Heinz Becker, Werner Berger and Günter Domschke, Addison-Wesley Pub. Co, 195-196, (1973)

Preparation of isobutyl bromide

Preparation of isobutyl bromide

2.56 moles, 244 ml of freshly distilled phosphorus tribromide are added to 7 moles of dry isobutyl alcohol at —10° C, with exclusion of water, with stirring and cooling in ice-salt, and at such a rate that the temperature remains below 0° C. After removal of the cooling bath the mixture is stirred until it reaches room temperature and is left overnight. The crude bromide is distilled by using 30-cm column at 50° C/200 mm. The distillate is cooled to 0° C and washed with concentrated sulfuric acid (3 x 50 ml) at 0° C and then shaken with dry potassium carbonate until the odor of hydrogen bromide has disappeared. It is distilled either through a 1-m column at atmospheric pressure (b.p. 91-93° C) or at 135 mm through a column with a reflux ratio of 5:1 (b.p. 41-43° C/135 mm), the yield of isobutyl bromide being 55-60%.

Org. Syn., Coll. Vol. II, 358 (1943).





InChI Key


Canonical SMILES


Depositor-Supplied Synonyms

1-Bromo-2-methylpropane, ISOBUTYL BROMIDE, 78-77-3, iso-Butyl bromide, Propane, 1-bromo-2-methyl-, Bromoisobutane, i-Butyl bromide, 1-Bromo-2-methyl-propane, UNII-5OEC0BW987, CCRIS 349, HLVFKOKELQSXIQ-UHFFFAOYSA-N, NSC 8416, EINECS 201-141-2, AI3-18130, isobutylbromide, i-butylbromide, iso-butylbromide, isobutyl-bromide, 2-methylbromopropane, sJPHAbIKUP@, 2-methylpropylbromide, iso-C4H9Br, 2-methyl bromopropane, 2-methylpropyl bromide, BrCH2CHMe2;, ACMC-1BLAD, l-bromo-2-methylpropane, 2-methyl-1-bromopropane, 3-bromo-2-methylpropane, AC1L1MSG, 1 -bromo-2-methylpropane, 1-bromo-2-methyl propane, AC1Q27JY, SCHEMBL7399, DSSTox_CID_31112, DSSTox_GSID_52539, KSC377A7R, 156582_ALDRICH, 5OEC0BW987, AC1Q1P25, CHEMBL346532, 58510_FLUKA, CTK2H7078, WLN: E1Y1&1, NSC8416, MolPort-001-779-904, BB_SC-6824, NSC-8416, ZINC1586727, Tox21_303878, ANW-37218, AR-1C1952, SBB059932, STL264117, ZINC01586727, AKOS000118762, EBD2638203, MCULE-6039420480, RP20323, RTC-030984, TRA0041920, UN 2342, CAS-78-77-3, ETHYL, 2-BROMO-1,1-DIMETHYL-, NCGC00357138-01, AN-23958, CJ-25284, KB-64977, OR034172, OR262696, SC-16381, LS-119649, TC-030984, A9430, B0616, FT-0085081, FT-0607463, FT-0627385, ST51046199, 3B4-0628, I14-0216, I14-108090, InChI=1/C4H9Br/c1-4(2)3-5/h4H,3H2,1-2H

Removed Synonyms

Bromoacetaldehydedimethylacetal, 2-Bromo-1,1-dimethoxyethane, CID6555, 7252-83-7, 83219-99-2

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