Laurolactam is an

organic compound Some chemical authorities define an organic compound as a chemical compound that contains a carbon–hydrogen or carbon–carbon bond; others consider an organic compound to be any chemical compound that contains carbon. For example, carbon-co ...

from the group of

macrocyclic Macrocycles are often described as molecules and ions containing a ring of twelve or more atoms. Classical examples include the crown ethers, calixarenes, porphyrins, and cyclodextrins. Macrocycles describe a large, mature area of chemistry. ...

lactam A lactam is a Cyclic compound, cyclic amide, formally derived from an amino alkanoic acid through cyclization reactions. The term is a portmanteau of the words ''lactone'' + ''amide''. Nomenclature Greek_alphabet#Letters, Greek prefixes in alpha ...

s. Laurolactam is mainly used as a monomer in

engineering plastic Engineering plastics are a group of plastic materials that have better mechanical or thermal properties than the more widely used commodity plastics (such as polystyrene, polyvinyl chloride, polypropylene and polyethylene). Engineering plastic ...

s, such as nylon-12 and copolyamides.T. Schiffer, G. Oenbrink: ''Cyclododecanol, Cyclododecanone, and Laurolactam.'' In: ''Ullmann's Encyclopedia of Industrial Chemistry.'' Wiley-VCH, Weinheim 2002, .

Synthesis

Although a derivative of 12-amino dodecanoic acid, it is made from

cyclododecatriene Cyclododecatrienes are cyclic trienes with the formula C12H18. Four isomers are known for 1,5,9-cyclododecatriene. The ''trans'',''trans'',''cis''-isomer is a precursor in the production of nylon-12. : Production The ''trans'',''trans'',''cis'' ...

. The triene is hydrogenated to the saturated alkane, cyclododecane. For the production of laurolactam, cyclododecane is oxidized with air or oxygen in the presence of

boric acid Boric acid, more specifically orthoboric acid, is a compound of boron, oxygen, and hydrogen with formula . It may also be called hydrogen orthoborate, trihydroxidoboron or boracic acid. It is usually encountered as colorless crystals or a white ...

and transition metal salts (e.g. cobalt(II) acetate), obtaining a mixtureH.-J. Arpe: ''Industrielle Organische Chemie.'' 6., vollst. überarb. Aufl., Wiley-VCH Verlag, Weinheim, 2007, . of cyclododecanol and

cyclododecanone Cyclododecanone is an organic compound with the formula (CH2)11CO. It is a cyclic ketone that exists as a white solid at room temperature. Like its smaller analogs but unlike the larger ones, it has a camphor-like odor. History and synthesis It ...

. This mixture is quantitatively dehydrogenated on a copper contact catalyst to

and this reacted with

hydroxylamine Hydroxylamine (also known as hydroxyammonia) is an inorganic compound with the chemical formula . The compound exists as hygroscopic colorless crystals.Greenwood and Earnshaw. ''Chemistry of the Elements.'' 2nd Edition. Reed Educational and Prof ...

to cyclododecanone oxime. The

oxime In organic chemistry, an oxime is an organic compound belonging to the imines, with the general Chemical formula, formula , where R is an organic Side chain, side-chain and R' may be hydrogen, forming an aldoxime, or another organic functional g ...

is rearranged to laurolactam in a

Beckmann rearrangement The Beckmann rearrangement, named after the German chemist Ernst Otto Beckmann (1853–1923), is a rearrangement reaction, rearrangement of an oxime functional group to substituted amides. The rearrangement has also been successfully performed on ...

in the presence of a strong acid. Laurolactam formation 2

An alternative process is the photonitrosation of cyclododecane with

nitrosyl chloride Nitrosyl chloride is the chemical compound with the formula NOCl. It is a yellow gas that is commonly encountered as a component of aqua regia, a mixture of 3 parts concentrated hydrochloric acid and 1 part of concentrated nitric acid. It is a str ...

in the presence of anhydrous hydrogen chloride. The resulting cyclododecanone oxime is extracted with concentrated sulfuric acid and rearranged to laurolactam by heating to 160 °C. The overall yield (photonitrogenation + Beckmann rearrangement) is up to 93%.

Properties

Laurolactam is a water-insoluble, crystalline solid; in technical quality usually beige colored and in pure state (99.9% purity) white. It is soluble in many organic solvents, e. g. 1,4-dioxane,

benzene Benzene is an Organic compound, organic chemical compound with the Chemical formula#Molecular formula, molecular formula C6H6. The benzene molecule is composed of six carbon atoms joined in a planar hexagonal Ring (chemistry), ring with one hyd ...

cyclohexane Cyclohexane is a cycloalkane with the molecular formula . Cyclohexane is non-polar. Cyclohexane is a colourless, flammable liquid with a distinctive detergent-like odor, reminiscent of cleaning products (in which it is sometimes used). Cyclohexan ...

. The purification process is carried out conventionally by multistage distillation under reduced pressure. The combination of distillation and crystallization from solution or melt yields very pure laurolactam (> 99%). The risk posed by laurolactam is considered to be low.

Uses

Ring opening polymerization is used to polymerize the monomer to nylon-12. The reaction can be brought about with cationic or anionic initiators or with water. Cationic polymerization with acid is believed to involve the initial O-protonation. Nucleophilic attack by the monomer on the reactive protonated nitrogen, followed by successive ring-opening acylation of the primary amine results in the formation of the polyamide. The

ring-opening polymerization In polymer chemistry, ring-opening polymerization (ROP) is a form of chain-growth polymerization in which the terminus of a polymer chain attacks cyclic monomers to form a longer polymer (see figure). The reactive center can be radical, anion ...

of the monomer laurinlactam initially proceeds upon the addition of water in a pre-polymerization at about 300 °C under pressure to a

prepolymer In polymer chemistry, the term prepolymer or pre-polymer, refers to a monomer or system of monomers that have been reacted to an intermediate-molecular mass state. This material is capable of further polymerization by reactive groups to a fully c ...

. This prepolymer is reacted in a subsequent polycondensation at ambient or reduced pressure and temperatures of about 250 °C to higher molecular weight polyamide 12 ( PA 12: - H-(CH₂)₁₁-COsub>n-). Polyamid12

As a comonomer, laurolactam is used together with

ε-caprolactam Caprolactam (CPL) is an organic compound with the formula (CH2)5C(O)NH. This colourless solid is a lactam (a cyclic amide) of caproic acid. Global demand for this compound is approximately five million tons per year, and the vast majority is used ...

for the preparation of copolyamide 6/12.

Drug Use

Laurolactam is used in the synthesis of MDL-12330A 0297-09-4 Although at first glance it appears as though Laurolactam is condensed with

cypenamine Cypenamine (INN, BAN), or cypenamine hydrochloride (USAN), also known as 2-phenylcyclopentylamine, is a psychostimulant drug which was developed by a group at the William S. Merrell Chemical Company in the 1940s. It is currently known only in s ...

, the authors stated that cis stereochemistry is chosen. The molecule is said to act as a

Calcium Channel Blocker Calcium channel blockers (CCB), calcium channel antagonists or calcium antagonists are a group of medications that disrupt the movement of calcium () through calcium channels. Calcium channel blockers are used as antihypertensive drugs, i.e., as ...

References

{{Reflist Lactams