Preparation of n-dodecane
Preparation of n-dodecane from n-hexyl bromide and sodium
23 grams of clean sodium are cut into small pieces and introduced into a dry 1000 ml round-bottomed flask, which is fitted with an efficient condenser and a dropping funnel. 70.5 ml (82.5 grams) of n-hexyl bromide (previously dried over anhydrous sodium or magnesium sulfate) are added in a dropping funnel and about 5 ml of n-hexyl bromide are introduced into the flask. If no reaction sets in, the flask gently warmed and the heating source is removed immediately when the reaction commences (the sodium will acquire a blue color). When the reaction subsides, the contents of the flask are mixed well, leading further reaction and some of the sodium may melt. A further 5 ml of n-hexyl bromide are added, and the contents of the flask are mixed. When the reaction has slowed down, the above process is repeated until all the 70.5 ml of n-hexyl bromide has been transferred to the flask. This can take up to 1.5 hours. Then the mixture is allowed to stand for 1-2 hours. Through the dropping funnel, 50 ml of ethanol dropwise over 1.5 hours are added, followed by 50 ml of 50% alcohol during 30 minutes, and 50 ml of distilled water over 15 minutes. During the addition, the reaction flask is mixed from time to time. 2-3 small pieces of porous porcelain are added and the mixture is reflux for 3 hours. During this time, any unreacted n-hexyl bromide will be hydrolyzed. In order to obtain n-dodecane, a large excess of water is added and the upper layer containing crude n-dodecane is separated. The crude product is washed once with an equal volume of water and dried with anhydrous magnesium sulfate. The crude n-dodecane is purified by distillation, collecting fraction boiling at 94° C/13 mm. The yield of n-dodecane is 37 grams.
All hydrocarbons prepared by the Wurtz reaction contain small quantities of unsaturated hydrocarbons. These may be removed by shaking repeatedly with 10% of the volume of concentrated sulfuric acid until the acid is no longer colored. The purified hydrocarbon is washed with water, 10% sodium carbonate solution, water (twice), and dried with anhydrous magnesium or calcium sulfate. The hydrocarbon is then distilled from sodium; two distillations are usually necessary to obtain a perfectly pure product. The residual sodium is destroyed by treatment with methanol.
A text book of practical organic chemistry, by A. I. Vogel, 236-237, 1974
DODECANE, n-Dodecane, 112-40-3, Dihexyl, Bihexyl, Adakane 12, N-Dodecan, n-Dodecan [German], Ba 51-090453, NSC 8714, CCRIS 661, CHEBI:28817, HSDB 5133, SNRUBQQJIBEYMU-UHFFFAOYSA-N, EINECS 203-967-9, BRN 1697175, 93685-81-5, dodecan, Dodekan, Duodecane, Normal Paraffin M, Norpar 13, C12-n-alkane;, C12-14-alkanes, Alkanes, C10-14, DSSTox_CID_6913, AC1L1QG7, DSSTox_RID_78250, DSSTox_GSID_26913, KSC175C3D, CHEMBL30959, D221104_ALDRICH, UNII-11A386X1QH, 297879_ALDRICH, 442671_SUPELCO, WLN: 12H, Jsp000956, CH3(CH2)10CH3, 44010_FLUKA, 44030_FLUKA, CTK0H5131, NSC8714, D221104_SIAL, MolPort-001-783-725, 11A386X1QH, 44030_SIAL, CH3-[CH2]10-CH3, 297879_SIAL, NSC-8714, EINECS 297-629-8, Tox21_303615, ANW-16463, LMFA11000004, STL280320, AKOS015904160, DB02771, EBD2203394, MCULE-3947157412, RTR-002427, TRA0025406, NCGC00166012-01, NCGC00257481-01, AN-22698, CAS-112-40-3, DA-16704, LS-63438, U215, TR-002427, D0968, FT-0625568, S0284, C08374, 4-01-00-00498 (Beilstein Handbook Reference), 1310FACD-F2BF-4FD7-BC20-B21DF06EDE79, 3B4-0754, I14-17881, I14-107531, UNII-FW7807707B component SNRUBQQJIBEYMU-UHFFFAOYSA-N, Hydrocarbons, C4, 1,3-butadiene-free, polymd., triisobutylene fraction, hydrogenated, InChI=1/C12H26/c1-3-5-7-9-11-12-10-8-6-4-2/h3-12H2,1-2H, 93924-07-3
Pentadecane, oleic acid, UPL