Uses
Lauroyl chloride is used as tailoring agent for chemical modification of nanocelluloses of different length, nanofibrillated cellulose and cellulose nanocrystals and in the preparation of acylated collagen with water solubility and better surface activity. It is also employed as organic low-friction boundary lubricant in the preparation of novel polyvinyl alcohol hydrogel.It is used in the synthesis of hemicellulose-based hydrophobic biomaterials.
Application
Dodecanoyl chloride aslo known as lauroyl chloride is an acid chloride that can be used as a reagent for the surface modification of:
Chitosans, by converting it into acylated chitosans for increasing solubility in organic solvents.
Microfibrillated cellulose (MFC) for improving dispersibility in biopolyamide nanocomposites.
It can also be used as a:
Starting material for the synthesis of (R)-3-aminotetradecanoic acid (iturinic acid).
Reagent for the preparation of (3,6-bis(dodecanamido)-2,7-dibromo-9-dodecyl-9H-carbazole).This amide intermediate can be further used in the synthesis of azomethine-bridged ladder-type poly( p-phenylene)s.
Preparation
Equipment: A 500-mL, roundbottomed flask was fitted with a paddle stirrer, a gas inlet tube, a thermowell, and a dry ice/acetone deflamator (dry-ice condenser). The flask and fittings were arranged so that gaseous phosgene could be fed in below the surface of the stirred reaction medium, and that phosgene escaping from the hot medium could be condensed on the dry-ice/acetone deflamator and returned directly to the medium as a liquid. The deflamator was connected to two dry-ice/acetone traps in series, which, in turn, were connected to a water scrubber, and the scrubber was open to the atmosphere within the confines of a fume hood. (Caution! Phosgene is not sufficiently irritating at time of exposure to give warning of lethal amounts.) As byproducts, hydrogen chloride and carbon dioxide were evolved from the reaction medium; they passed up through the deflamator, through the dry-ice/acetone trap, and into the top of the water scrubber. In the scrubber, the gases reacted with a steady stream of water and passed down through a long glass column (4 ft) packed with glass beads. If the rate of phosgenation was too rapid, e.g. an excessive reaction temperature occurred, phosgene entrained in the by-product gases was no longer adequately condensed by the deflamator and began to appear in the dry ice/ acetone trap. To this end, the incorporation of these traps in the off-gas system helps to establish facile reaction conditions.
Reaction: The flask was charged with lauric acid 1330 (200 g, 1.0 mol) and catalyst (imidazole, 2-methyl imidazole, 2.0 mol% based on the acid), and the mixture was heated with stirring to 90 C°. The stirred mixture was maintained at 90 C° for 1 h, at which time gaseous phosgene was introduced below the surface of the liquid at such a rate as to maintain a gentle phosgene reflux from the deflamator. Phosgene addition was regulated and calculated with the aid of a tubular flowmeter. The reaction was continued, generally within the temperature range 80–100 C°, until hydrogen chloride was no longer evolved (cessation of heat generation at the top of the water scrubber). The phosgene feed was stopped and the reaction mixture was kept at 85–95 C° with gentle phosgene reflux from the deflamator until the evolution of carbon dioxide had ceased (30–60 min, as evidenced by cessation of the gas entering at the base of the scrubber column). Occasionally, additional phosgene was required during this period to maintain phosgene reflux and to complete the reaction. Following complete reaction, the deflamator was replaced by a 10-in. (25 cm) glass helix packed distillation column fitted with a total reflux head, and dissolved phosgene was removed from the stirred reaction product by purging with dry nitrogen at 90 C° for 2 h. The product was distilled at 10 mmHg as a single fraction. Yield: 91–94.5% of lauroyl chloride 1331.
The SNPE Group has developed efficient catalysts and a clean technology for the industrial manufacture of acid chlorides with phosgene. Mechanistic studies demonstrated that the activity of the catalysts is related to the nucleophilicity of the chloride anion. Based on these findings, hexaalkylguanidinium chlorides 1332 proved to be efficient and powerful phosgenation catalysts (HBGCl) for converting either carboxylic acids or their anhydrides to acid chlorides. Particularly well-suited for chlorination reactions with phosgene is the silica-supported catalyst PBGSiCl.
Reactions
Lauroyl chloride is a substrate for diverse reactions characteristic of acid chlorides. With base, it converts to laurone, a ketone with the formula [CH3(CH2)10]2CO. With sodium azide, it reacts to give undecyl isocyanate via a Curtius rearrangement of the acyl azide.
