Diamines trans

Qiana, introduced by Du Pont in 1968 but later withdrawn from the market, was made from bis(4-aminocyclohexyl)methane and dodecanedioic acid. This diamine exists in several cis—trans and trans—trans isomeric forms that influence fiber properties such as shrinkage. The product offered silk-like hand and luster, dimensional stabiUty, and wrinkle resistance similar to polyester. The yam melted at 280°C, had a high wet glass-transition temperature of - 85° C and a density of 1.03 g/cm, the last was lower than that of nylon-6 and nylon-6,6. Qiana requited a carrier for effective dyeing (see Dye carriers). 

Table 3 fists cycloaliphatic diamines. Specific registry numbers are assigned to the optical isomers of /n t-l,2-cyclohexanediamine the cis isomer is achiral at ambient temperatures because of rapid interconversion of ring conformers. Commercial products ate most often marketed as geometric isomer mixtures, though large differences in symmetry may lead to such wide variations in physical properties that separations by classical unit operations are practicable, as in Du Font s fractional crystallisation of /n t-l,4-cyclohexanediamine (mp 72°C) from the low melting (5°C) cis—trans mixture. 

Methylenediandine (4) (MDA) /7(9/-77-5 7hydrogenation to methylenedi(cyclohexylamine) generates first the <7j -(6) and trans-Q isomers of half-reduced 4-(7-aminohen7y1)-cyc1ohexy1amine (5) [28480-77-5] a differentially reactive diamine offered ia developmental quantities by Air Products and Chemicals. 

Conditions cited for Rh on alumina hydrogenation of MDA are much less severe, 117 °C and 760 kPA (110 psi) (26). With 550 kPa (80 psi) ammonia partial pressure present ia the hydrogenation of twice-distilled MDA employing 2-propanol solvent at 121°C and 1.3 MPa (190 psi) total pressure, the supported Rh catalyst could be extensively reused (27). Medium pressure (3.9 MPa = 566 psi) and temperature (80°C) hydrogenation usiag iridium yields low trans trans isomer MDCHA (28). Improved selectivity to aUcychc diamine from MDA has been claimed (29) for alumina-supported iridium and rhodium by iatroduciag the tertiary amines l,4-diazabicyclo[2.2.2]octane [280-57-9] and quiaucHdine [100-76-5]. 

Dicyclopentadiene (24) [77-73-6] is an inexpensive raw material for hydrocyanation to (25), a mixture of l,5-dicarbonittile [70874-28-1] and 2,5-dicarbonittile [70874-29-2], then subsequent hydrogenation to produce tricyclodecanediamine, TCD diamine (26). This developmental product, a mixture of endo and exo, cis and trans isomers, is offered by Hoechst. 

The polyamide copolymer of dodecanoic acid with methylenedi(cyclohexylamine) (MDCHA, PACM) was sold as continuous filament yam fiber under the tradename QIANA. As late as 1981, over 145,000 t was produced using high percentages, typically 80%, of trans, trans MDCHA isomer. The low melting raffinate coproduct left after t,t isomer separation by fractional crystallisation was phosgenated to produce a Hquid aUphatic diisocyanate marketed by Du Pont as Hylene W. Upon terrnination of their QIANA commitment, Du Pont sold the urethane intermediate product rights to Mobay, who now markets the 20% trans, trans—50% cis, trans—30% cis, cis diisocyanate isomer mixture as Desmodur W. In addition to its use in polyamides and as an isocyanate precursor, methylenedi (cyclohexyl amine) is used directiy as an epoxy curative. The Hquid diamine mixture identified historically as PACM-20 is marketed as AMICURE PACM by Anchor Chemical for performance epoxies. 

The main use of acrolein is to produce acrylic acid and its esters. Acrolein is also an intermediate in the synthesis of pharmaceuticals and herhicides. It may also he used to produce glycerol hy reaction with isopropanol (discussed later in this chapter). 2-Hexanedial, which could he a precursor for adipic acid and hexamethylene-diamine, may he prepared from acrolein Tail to tail dimenization of acrolein using ruthenium catalyst produces trans-2-hexanedial. The trimer, trans-6-hydroxy-5-formyl-2,7-octadienal is coproduced. Acrolein, may also he a precursor for 1,3-propanediol. Hydrolysis of acrolein produces 3-hydroxypropionalde-hyde which could he hydrogenated to 1,3-propanediol. ... 

Step 1 of Figure 29.14 Transimination The first step in transamination is trans-imination—the reaction of the PLP—enzyme imine with an a-amino acid to give a PLP—amino acid imine plus expelled enzyme as the leaving group. The reaction occurs by nucleophilic addition of the amino acid -NH2 group to the C=N bond of the PLP imine, much as an amine adds to the C=0 bond of a ketone or aldehyde in a nucleophilic addition reaction (Section 19.8). The pro-tonated diamine intermediate undergoes a proton transfer and expels the lysine amino group in the enzyme to complete the step. 

Pimelic Acid (Heptanedioic Acid or 1,5-Pentane-dicarboxytlc Acid). HOOC.(CH2)s.COOH mw 160.17 white prisms mp 106° bp 272° at 100mm (subl), and 212° at 10mm d 1.329 g/cc at 15°. Sol in w, ethanol, eth and hot benz. Prepn is by oxidn of cycloheptanone, capric acid or oleic acid treatment of salicylic acid with Na in amyl ale, or by decarboxylating 1,1,5,5-pentanetetracarboxylic acid with heat Pimelic acid has been combined with cis and trans-, 4-cyclohexanediol to give polyesters, and with m-xylene-ce,ol -diamine or poly-methylenediamines to form polyamides. With diperoxides, the acid forms resins. It is also used as the parent compd to form the expls presented below... 

The chemoenzymatic synthesis of the analgesic U-(—)-50,488 [41] and new C2-symmetric bisaminoamide ligands derived from N,N-disubstituted trans-cyclohexane, ,2-diamine [41] has been possible by a CALB-catalyzed resolution using ethyl acetate as solvent and acyl donor [42]. 

Scheme 7.22 Mechanism of the sequential kinetic resolution of trans-cyclohexane-1,2-diamine.

By heating 2-benzyloxycyclohexanone 208 and (R)-l-phenylethylamine in refluxing toluene for 4 days in a Dean-Stark apparatus, the imine 209 was formed, then a rearrangement occurred to give first the a-aminocyclohexanone derivative 210 and finally the Q, o -disubstituted imine 211 with moderate diastereoselectivity. Reduction of this imine with sodium borohydride gave a mixture of two trans diamines (S,S)-212 and (R,R)-212, which were separated by chromatography. The enantiomers of 1-benzyl-1,2-diaminocyclohexanes 213 were then obtained by hydrogenolysis [99] (Scheme 31). 

Entry 3 involves a catalyst derived from (/ , Trans-cyclohexane- 1,2-diamine. The square planar Cu2+ complex exposes the re face of the dienophile. As with the BOX catalysts, this catalyst has c2 symmetry. 

Preparation of ligand 31 Originally, chiral ligand 31 was prepared from (1R,2R)-1,2-diaminocydohexane 33 based on the racemic synthesis reported by Barnes et al. in 1978 [15], where picolinic acid 34 was activated with P(OPh)3 and then coupled with trans-l,2-diaminocyclohexane. The reported isolated yield in the case of racemate was only 47%. We optimized the preparation as shown in Scheme 2.8 [16]. Picolinic acid 34 was activated with CDI in THF. After confirmation of activation, chiral diamine 33 was added to the solution. When complete, the reaction was quenched via the addition of a small amount of water (to quench excess CDI). The reaction solvent was then switched from THF to EtOH, when the desired ligand 31 directly crystallized out. Ligand 31 was isolated in 87% yield by simple filtration of the reaction mixture in high purity. With a 22 litter flask, 1.25 kg of 31 was prepared in a single batch. 

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