1-phenylethylamine perchlorate

ABSTRACT. The chiral recognition properties of chiral 18-crown-6 ethers with phenyl, l naphthoxymethyl, l naphthylmethyl, or 2,3,5,6-tetra-methylphenylmethyl substituents for a-phenylglycine methyl ester and 1-phenylethylamine perchlorate were investigated by a standard extraction procedure. The chiral recognition factor of 1-naphthoxymethyl substi-tuted crown ether is 2.0 for the former salt but near 1.0 for the latter, whereas that of the other crown ethers is not so dependent on the structure of salts, which indicates the importance of the mutual relation of the structure of host and guest molecules. 

Chiral recognition for 1-phenylethylamine perchlorate(6). Extraction of aqueous 1-phenylethylamine perchlorate(6) with crown ethers(4) and the determination of the amount of extracted amine was carried out by the same procedure as described for a-phenylglycine methyl ester perchlorate. Another 10 ]ll portion of organic phase was derivatized with (-)-(L) N-trifluoroacetylalanine and used for the determination of CRF by GLC(OV-17 coated glass capillary column at 160 °C). 

The chiral recognition properties of crown ethers(4) for racemic Ct-phenylglycine methyl ester perchlorate(5) and 1-phenylethylamine perchlorate(6) were tested by standard extraction experiments.No appreciable amount of crown ethers was detected in aqueous layers. The relative amount of complexed salts to crown ethers in CDCl layers was determined by NMR integrations. When (5) is complexed with (4), the signal of ester methyl protons is moved and separated into two signals for each enantiomei When (6) is complexed with (4), the signal of methyl protons(doublet) is only shifted but not separated. The ratio of enantiomers of complexed salts was determined by HPLC using a chiral column for (5) or by GLC for (6) as diastereomeric isomers of (-)-(L)-N-trifluoroacetylalanine. The results are summarized in Table I and II. 

Table II. Chiral recognition properties of crown ethers for 1-phenylethylamine perchlorate ...

Chiral 2,4-dimethyl-3-(l-phenylethyl)thiazolium perchlorates were prepared from the available chiral 1-phenylethylamines and used to prepare optically active monomethinecyanines, but not spiropyrans.195... 

To a solution of 2-phenylethylamine (0.121 g, 1.0 mmol) in DMF (20 mL) was added dropwise a solution of l,2,3-lris(7ert-butylsulfanyl)cyclopropenylium perchlorate (0.403 g, 1.0mmol) in DMF (lOmL) at rt. After stirring for 0.5 h, 50% NaH in mineral oil (0.144 g, 3.00 mmol) was added, and the mixture was heated at 80"C for 1 h. The resulting solution was poured into H2O (200 mL) containing a small amount of NaCl, extracted with EtjO/hexane, dried, and concentrated under reduced pressure. The residue was chromatographed (silica gel, hexane/CH Cl 1 1) and recrysiallized (hexane) to give colorless crystals yield 0.210 g (65%) mp 82 C. 

In the present paper, we report the synthesis of chiral 18-crown-6 ethers with aromatic substituents of various rigidity and bulkiness, and the effects of substituents on their chiral recognition properties for 1-phenylethylamine and a-phenyl glycine methyl ester perchlorate. ... 

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