8 1,6-Diaminohexane

Adiponitnle (hexanedinitnle, dicyanobutane, ADN), NC(CH2)4CN, is manufactured principally for use as an intermediate for hexamethylenediarnine (1,6-diaminohexane), which is a principal ingredient for nylon-6,6. However, in 1996, BASF aimounced the development of a process to make caprolactam from adiponitrile (44,45). Caprolactam is used to produce nylon-6. The implementation of this technology could increase the demand for adiponitrile dramatically. 

Condensation polymerization of amines with carboxylic acids leads to the polyamides, substances more commonly known as nylons. A common polyamide is nylon-66, which is a polymer of 1,6-diaminohexane, H2N(GH2)6NH2, and adipic acid, HOOC(CH2)4COOH. The 66 in the name indicates the numbers of carbon atoms in the two monomers. 

Copolymers are polymers made up of more than one type of repeating unit (Fig. 19.14). One example is nylon-66, in which the repeating units are formed from 1,6-diaminohexane, H2N(CH2)(lNH2, and adipic acid, HOOC(CH2)4COOH. They form an alternating copolymer, in which acid and amine monomers alternate. 

Fatty acid amides of isophorone diamine, 2,5-diaminonorbomylene, and 2,2,4-trimethyl-1,6-diaminohexane are particularly suitable for high-tempera-ture and high-pressure applications [971],... 

Various amine salts, such as hydrochlorides of 1,6-diaminohexane, 1,12-diamino-dodecane, 1-aminododecane and a bisulphate adduct of 1,6-di-isocyanatohexane. This was an attempt to introduce a final reactive step to form crosslinks between unfixed dye molecules on the fibre [193]. 

Guanaranta and Wilson [111] compared the different methods for immobilization of acetylcholinesterase by direct immobilization on the matrix, introduction of 1,6 diaminohexane as a spacer, and two methods of oriented immobilization via antibody and avidin-biotin linkage. They found that the latter gave the best efficiency, i. e., tenfold higher than direct immobilization on the matrix (which was the lowest) followed by immobilization on the antibody and immobilization using a spacer. Details about the biotin-avidin technology were published by Wilchek and Bayer [112]. 

It is important to emphasize that the introduction of a spacer should never affect the binding characteristics of the support. The selected spacer must not introduce any charges and should not be sufficiently hydrophobic to cause any kind of non-specific interaction. Several molecules can fulfill this demand but only a few of them are regularly used. Most of these contain terminal amino or carboxylic groups. In particular these are diaminodipropyl amine, 6-aminocapronic acid, 1,6-diaminohexane, ethylenediamine, l,3-diamino-2-propanol, succinic acid, 1,4-butanediol diglycidyl ether, and others [96]. Extensive description of other bifunctional reagents can be found in the book of Wong [89]. 

The last acyclic diamine we will discuss is 1,6-diaminohexane or hexamethylenedi-amine (26). How much interaction is there between the two amino groups The desired enthalpy of formation is available in both condensed phases43, —205(s) and — 164(lq). If all hydrogen bonding and any other intersubstituent interaction were negligible, then reaction 29 would be thermoneutral. 

M. Berode, B. Testa, H. Savolainen, Bicarbonate-Catalyzed Hydrolysis of Hexameth-ylene Diisocyanate to 1,6-Diaminohexane , Toxicol. Lett. 1991, 56, 173 - 178. 

Nylon-66 is made by the condensation polymerization of the dicarboxylic acid adipic acid, and 1,6-diaminohexane, an amine. (The number 66 comes from the fact that each of the two reactants contains six carbon atoms.) This reaction results in the formation of amide bonds between monomers, as shown in Figure 2.13. Condensation polymers that contain amide bonds are called nylons or polyamides. Condensation polymers that contain ester bonds are called polyesters. Polyesters result from the esterification of diacids and dialcohols. 

Nylon-66 is made from adipic acid and 1,6-diaminohexane. 

For unsymmetrical diisonitrile 101, reaction with both glutaric acid and octanedioic acid, and isobutyraldehyde and isopropylamine afforded macrocycle 105a and 105b, respectively, in reasonable yield. Reaction of 101 with 1,6-diaminohexane, acetic acid and isobutyraldehyde yielded 106 in a very acceptable 51% yield (Scheme 18). 

In a second series of experiments of type 1, the influence of the nature of the diamine on the rate of ZSM-48 crystallization has been examined (Table 2). Compared with the hydrogel involving 1,6 diaminohexane, ZSM-48 crystallizes more rapidly when 1,8 diaminooctane is present in the hydrogel. Probably the lenght of the diaminooctane chain is better accomodated into the channels of ZSM-48 zeolite as to achieve a more complete pore volume filling. Indeed, the channel length per unit cell of... 

ZSM-48 is 16.8 A while the length of 1,6 diaminohexane and 1,8 diaminooctane is 11.51 and 14.02 A respectively. The zeolite therefore prefers diaminooctane as pore filler. 

A Kjeldahl flask was charged with ,/V -dimethyl-1,6-diaminohexane (5.75 mmol) dissolved in 10 ml of THF and then treated with the dropwise addition of -butyl-lithium (5.75 mmol) while vigorously stirring. This solution was then treated with chlorotrimethylsilane (5.75 mmol) and stirred at ambient temperature for 30 minutes and then filtered off through a poly(tetrafluoroethylene) (PTFE) filter and 15 mL of the filtrate charged into a 150-ml glass bottle. This aliquot was then treated with tetramethylethylene diamine (4.23 mmol) and n-butyllithium (4.23 mmol) and used immediately as a polymerization initiator. 

Diaminodiethylamine 1,6-Diaminohexane 1,1 l-Diamino-3,6,9-Triazaundecane Diammonium Citrate Diammonium Hydrogen Phosphate Diammonium Orthophosphate Diammonium Oxalate Diamyl Phthalate Di-N-Amyl Phthalate... 

---