Reaction #718202

Reaction equation

succinimide

N-bromosuccinimide

AIBN

Linoleic acid

→

11-Bromolinoleic acid

Solvents

carbon tetrachloride

Conditions

Workup

1. 1
   Dryingdried over P2O5
2. 2
   Temperaturewith gentle heating till the reaction
3. 3
   Other(about 1 h in total)
4. 4
   Filtrationthe precipitate filtered off
5. 5
   Washwashed with CCl4 (2×5 ml)
6. 6
   OtherThe combined organic fractions were evaporated

Procedure

Linoleic acid (7 g, 25 mmol, Aldrich) was dissolved in 25 ml of carbon tetrachloride dried over P2O5. N-bromosuccinimide (4.425 g, 25 mmol, desiccated overnight over P2O5) and 0.05 g AIBN were added, and the reaction mixture in a flask with a reversed condenser was stirred with gentle heating till the reaction was initiated as manifested by an intense boiling (if the reflux is too intense the heating should be decreased). When succinimide stopped accumulating on the surface, the heating was continued for another 15 min (about 1 h in total). The reaction mixture was cooled to RT and the precipitate filtered off and washed with CCl4 (2×5 ml). The combined organic fractions were evaporated and the 11-Bromolinoleic acid obtained was gradually added to a solution of NaBD4 (390 mg, 10 mmol) in 30 ml of isopropanol. After an overnight stirring, a diluted solution of HCl was slowly added till there was no more deuterium gas produced. Upon a standard workup, the mono-deuterated acid was brominated and reduced again to yield a target di-deutero derivative (bp 230-231° C./15 mm, 4.4 g, 63%). MALDI-TOF MS: mono-bromo derivative, found: 358.202, 360.191 (doublet, approx 1:1, MI); di-deutero delivative, found: 282.251 (MI).

Source