Phenylethylamine, derivatives, comparison

Dimethylamine (109), putrescine (111), and spermidine (110), isolated from various insects (Table VIII), were obtained as p,p -nitrophenylazobenzoyl, p-phenylazobenzenesulfonyl, and I-dimethylaminonaphthalene-5-sulfonyl (dan-syl) derivatives and picrates or were detected by high-performance liquid chromatography (HPLC) using the ion-exchange resin (106,343). V,V-Dimethyl-3-phenylethylamine (131) from spiders of the genus Sclerobunus (Table VIII) has been identified by mass spectral comparison with a synthetic sample (117). 

One of the earliest comparisons of thiophene to benzene in a biological system compared the vasoconstrictor activity of phenylethylamine (362 Ar = Ph) with that of 2-thienyIethyl-amine (362 Ar = 2-thienyl). It was shown to have vasopressor activity in the cat, but was only about one-tenth as potent. Phenylalanine is an essential amino acid for the growth of yeast, bacteria and mammals. It was found that /3-2-thienylalanine (363 Ar = 2-thienyl) was an antimetabolite of this essential amino acid, and numerous studies on the active L-form and simple peptides derived from it have been made. 

This correlation (Scheme 13.10) had originally been performed by Leithe,W. Chem. Ber., 1931, (54,2827 by benzoylation of the (-)-l-phenylethylamine, nitration of the aromatic ring of the resulting At-benzoyl derivative, reduction of the nitro group to the amine, diazotization of the amine and conversion of the diazo compound to the phenol. Oxidation of the phenol with chromic anhydride in acetic acid yielded the A -benzoyl derivative of (-F)-alanine—by direct comparison to that compound. 

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