Phenylethylamine polymer

Particularly, also, for that reason a hydrolytic cleavage of the active substance seems to be most unlikely, because the same group of scientists has been able to show that poly[2-(4-vinylphenyl)ethylamine] [28], which certainly cannot hydrolyze, shows also a weak activity. However, this polymer is essentially more toxic than 2-phenylethylamine, and thus, the comparison is difficult (98). 

The converse approach to inducing chirality into conducting polymer chains, namely, the incorporation of an optically active cation, has also been successfully employed in our laboratories to produce the first optically active water-soluble sul-fonated PAn. Poly(2-methoxyaniline-5-sulfonic acid) has been prepared in optically active form through the electropolymerization of 2-methoxyaniline-5-sulfonic acid in the presence of (/ )-(+)- or (.S )-(-)-l-phenylethylamine.29 The optical activity and electroactivity of the chiral sulfonated PAn s are retained when immobilized on poly(4-vinylpyridine) (see Chapter 5). 

The throughput of the system was subsequently doubled as a result of employing polymer-supported scandium triflate [PS-Sc(OTf)2] (79) as the Lewis acid catalyst, under the aforementioned reaction conditions. Using this approach, the authors demonstrated the generality of the technique, synthesizing a 10 x 5 array of a-aminonitriles, derived from 10 aliphatic and aromatic aldehydes and five amines. The chemoselectivity of the technique was also demonstrated using the reaction of 4-acetylbenzaldehyde (80) and 2-phenylethylamine (81) (Scheme 6.22) whereby 2-(4-acetylphenyl)-2-(phenethylamino)acetonitrile (82) was obtained, in 99.8% yield, as the sole reaction product. 

Optically active poly meth(acryl) amides were synthesized under solvent-free conditions by microwave heating of a mixture of meth(acrytic) add and (R)-l-phenylethylamine in the presence of 2,2 -azoisobutyronitrile (AIBN) as a free radical initiator (Scheme 3.7). Characterization of the prepared materials revealed the presence of imide moieties, presumably due to the high reaction temperatures achieved and, as a result, facile intramolecular dehydration. Interestingly, in the case of the acrylic acid derivatives, the molecular weight of the obtained polymers was found to be inversely proportional to the applied microwave power. 

Biologically active substances have been linked to polyphosphates via ionic bonds between the substance and the polymer (Scheme 6.16). Troev and co-workers have reported the successful immobilization of drugs such as 2-phenylethylamine, cysteamine, and bendamustine hydrochloride, leading to enhanced stability and a lower cytotoxicity of the polymer-drug complexes than the pure analogs. 

Figure 2.16 Electrostatic interaction of chiral ammonium ion of phenylethylamine to ionized sulfonate groups along the polymer backbone. (Reprinted from Synthetic Metals, 106, E. V. Strounina, L. A. P. Kane-Maguire, G. G. Wallace, 129. Copyright (1999), with permission from Elsevier.)...

The same authors also found the catalytic effect of la in the reduction of acetophenone oxime O-methyl ether, showing that the use of 10 mol% of la afforded product amine with 52% ee [81], Polymer-supported OABs were also very effective for the same reduction to give (S)-l-phenylethylamine with 99% ee [31]. Interestingly, the absolute configurations of the amines formed depend on the geometry of the oxime ethers the E oxime led to the S amine, while the Z oxime gave rise to the R amine (Scheme 11.18) [82],... 

Figure 9 Synthesis of chiral polymers from (/ )-/V-(1-phenyl-ethyl)methacrylamide and methacrylic acid and (/ )-1-phenylethylamine.

We have succeeded in introducing asymmetry into the main chain of a polymer by radical polymerization [20] of the optically active a-phenylethylamine salt of trans butadiene-1-carbonic acid (Bu-l-acid). By radical polymerization of Bu-l-acid, a 1,4-trans structure polymer is obtained, and the amine salt of Bu-l-acid also polymerizes with 1,4-trans addition. 

Other OAP (polymers 2,354,5) may be obtained starting from polystyrene (cross-linked with 2% DVB, bead polymer, grain size 200—400 mesh) followed by chlorosul-phonation [4] resp. chloromethylation [5] and subsequent reaction with D-ephedrine or D-a-phenylethylamine [6]. 

As racemic mixtures DL-mandelic acid (I), DL-2-phenyl glycine hydrochloride (VII), and DL-phenylethylamine hydrochloride (X) were chosen. Water was used as eluant. With both adsorbants only the unchanged racemic mixtures were recovered. But as expected after saponification of polymer 9 to 11, DL-mandelic acid (I) and DL-2-phenyl glycine (VII) could be partially resolved. Polymer 11 is similar to 7, but it contained practically no SOaH-groups. 

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