Sulfuric acid dodecyl , extraction

A mixture of 125 g. (0.5 mole) of w-dodecyl bromide (Note 1), 38 g. (0.5 mole) of thiourea, and 250 cc. of 95 per cent ethyl alcohol is refluxed on a steam cone for three hours (Notes 2, 3, and 4). A solution of 30 g. (0.75 mole) of sodium hydroxide in 300 cc. of water is added, and the mixture is refluxed for two hours. During this period the mercaptan separates as a pink to red oil. The layers are separated, and the aqueous layer is acidified with dilute sulfuric acid (7 cc. of concentrated acid to 50 cc. of water) and then extracted with one 75-cc. portion of benzene (Note 5). The extract is added to the crude mercaptan layer, and the whole is washed twice with 200-cc. portions of water and... 

Extraction of PSA and H5DTPA. Figure 3 also shows the D s for dodecyl sulfuric acid (DSA) (the acidic form of the commonly used detergent, sodium dodecyl sulfate) and diethylenetriamine-pentacetic acid (H5DTPA). Both of these compounds could be constituents in a salt waste treatment facility of a fuel reprocessing plant (1) and therefore were included in the study. 

Dodecanethiol 271 A mixture of dodecyl bromide (125 g, 0.5 mole), thiourea (38 g, 0.5 mole), and 95 % ethanol (250 ml) is heated for 3 h on the steam-bath, then treated with a solution of sodium hydroxide (30 g, 0.75 mole) in water (300 ml) and heated for a further 2 h at the b.p. Some of the thiol separates and is removed from the aqueous layer, which is then acidified with dilute sulfuric acid (7 ml of concentrated acid in 50 ml of water), and extracted with benzene. The benzene (75 ml) extract and the previous layer of crude thiol are united, washed with two portions (each 200 ml), of water dried over anhydrous sodium sulfate (20 g), and fractionated. This gives 79-83 % (80-84 g) of 1-dodecanethiol, b.p. 165-169°/39mm. 

---