Isoamyl bromide

Isoamyl bromide boils at 118°, and has the specific gravity 1.219 at 15°. The yield is about 66 per cent of the theoretical calculated from the alcohol used. 

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Isoamyl bromide (l-hutyl-3-methyl bromide) [107-82-4] M 151.1, f -112 , b 119.2 / 737mm, d 1.208, n 1.444. Shaken with cone H2SO4, washed with water, dried with K2CO3 and fractionally distd. 

Iso-Amyl Bromide. Proceed as for n-Amyl Bromide, but use 88 g. (109 ml.) of synthetic (Sharpies) tsoamyl alcohol, b.p. 129-5-131°. Distil the piuified product through a fractionating column and collect the isoamyl bromide at 117-120° (125 g.). 

Isoamyl acetate, i91 Isoamyl alcohol, ml63 seolsoamyl alcohol, ml64 Isoamyl bromide, b362 Isoamyl chloride, cl69a Isoamyl nitrite, i92... 

Isethionic acid, hi 14 Isoamyl acetate, i80 Isoamyl alcohol, ml55 seolsoamyl alcohol, ml 56 Isoamyl bromide, b305 Isoamyl iodide, i42 Isoamyl nitrite, i81... 

Chloropentane 3-Bromopeotane I+)-2-M ethyl butyl bromide Isoamyl bromide Isoamyl iodide... 

Germanium tetra-isoamyl, Ge(C H x)a- —Sixty-flve grams of isoamyl bromide are slowly added to 9-6 grams of magnesium suspended in ether. The ether is i eplaced by dry benzene and 11 grams of germanium tetrachloride in benzene added, after which the mixture is boiled for three hours. Decomposition is effected in the usual manner and the solvents are eliminated by distillation. The residue is a heavy oil, which decomposes when distilled at ordinary pressure. At 10 mm. it boils mostly at 163 to 164 C. The yield of germanium tetra-isoamyl is 87 per cent. density 0-9147 at 20 C. n 1-457 at 17-5 C. 

Isoamyl bromide, b.p. 120-120.5°, was prepared as previously described. The product was fractionated through a packed column, such as that referred to in Note 9 below, to remove small quantities of tert.- my bromide arising from sec.-butyl carbinol present in the isoamyl alcohol. 

There are totally different reaction conditions in the [l,2,4]-elimination of HBr from isoamyl bromide (154), achieved by electron bombardment , which presumably proceeds via a carbocation C5H as intermediate and yields predominantly 13141). In the solvolysis of 155 an alkyl migration occurs and 156 is formed (17%)89). 

Calculate the theoretical yield from the isoamyl bromide used and the percentage obtained in the experiment. 

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