Alanine, DL-Phenyl

Synthesis. Using hexamethyl amine as initiator, we have copolymerized, in DNF solution, the N-carboxy-anhydride [NCA] of benzyl -L-glutamate with the NCAs of the following amino acids cinnamyl-L-glutamate, carbobenzoxy-L-lysine, L-leucine, dL-phenyl alanin, L-phenyl alanin. 

Ni-carbonyl as allylophilic reagent added all at once to a mixture of -decyl allyl carbonate, TMEDA, and dry, argon-satd. dimethylformamide, the stirred mixture warmed slowly to 55°, and the product isolated after 4 hrs. 1-decanol. Y 95%. - Similarly in the presence of water N-Allyloxycarbonyl-dl-phenyl-alanine dl-phenylalanine. Y 83%. F. e. s. E. J. Corey and J.W. Suggs, J. Org. Chem. 38, 3223 (1973). 

Definite proof of the conversion was obtained in isotopic experiments by Moss and Schoenheimer (185). These authors fed deutero-DL-phenyl-alanine to the rat and isolated the correspondingly labeled L-tyrosine. The conversion occurred even when an excess of tyrosine was fed, indicating that it was an obligatory pathway for the catabolism of phenyl-anine. 

A very selective and potent depletor of tissue 5-HT, pora-chloro-DL-phenyl-alanine (pCPA), is a potent inhibitor of tryptophan hydroxylase, and has several mechanisms of action... 

Glycyl-dl-phenylalanine allowed to react 25 min. at 65° and pH 7.5 with cis-hydroxoaquotriethylenetetraminecobalt(III) ions in aq. soln. -> dl-phenyl-alanine. Y ca. 100%.—The N-terminal aminoacid moiety is selectively hydrolyzed and converted into an inert metal complex. This reaction may prove useful for the stepwise degradation of peptides. F. e. s. J. P. Collman and D. A. Buckingham, Am. Soc. 85, 3039 (1963). 

The exchange of a methyl group for a phenyl or benzyl group at the chiral centres of the polymers (polymers 6, 7, 8) was nearly without influence upon the resolution efficiency. In the case of the chiral centres of the racemic mixtures there was found a distinct effect We studied the resolution efficiency of polymer 11 at identical conditions as with the partially resolvable DL-2-phenyl glycine (VII) with DL-anine (VIII), and DL-phenyl-alanine (IX). Both the latter aminoacids were recovered after the elution (lA HCl or O.IV KOH) as unchanged racemic mixtures. 

The observation that DL-[2- C]phenylalaine and DL-[3- C]phenyl-alanine showed no incorporation of radiolabel into mesembrine established that phenylalanine is not converted to tyrosine and that these two aminoadds... 

Phenyl-4-benzyl-6-oxazolone. Ten grams of benzoyl-dl-/3-phenyl-alanine is heated on the steam bath for thirty minutes with 100 cc. of acetic anhydride. The solution is concentrated in vacuum, and the syrupy residue is dissolved in 100 cc. of petroleum ether, b.p. 60-110 . The solution is decanted from a small amount of insoluble material and is cooled. Practically pure 2-phenyl-4-benzyl-5-oxazolone crystallizes in long needles, m.p. 69-71° yield 7.5 g. (80%). 

An excellent source of readily available chiral auxiliaries is to be found in amino-acids, and Schollkopf and co-workers have once again used them to prepare lithiated dihydropyrazines (11). In particular, they have used L-valine, tert-leucine, and (5)-0,0-dimethyl-a-methyldopa in the synthesis of (i )-a-amino-acids from, for example, glycine. "" The same authors have also used the oxazinones (12) to give chiral (S )-a-alkyl-a-phenylglycines from DL-phenyl-glycines however, in this case 2-hydroxyalkanoic acids are used as the chiral auxiliaries. In a quite different approach, protected and lithiated glycine is converted into alanine by the methyl sulphate (13) in enantiomeric excesses approaching 40... 

The hydantoins (116 and 117) have been prepared from DL-j8-ferrocenyl-a-alanine and N - ferrocenyl methyl-AT-(a-carbethoxy-benzyl)urea, respectively.68 The Friedel Crafts reaction of ferrocene and 2-pyrroylchloride gave the ketone (118).112,113 The polarographic half-wave potentials of 118 and other related ferrocenes were measured113 and it was concluded that the ferrocene radical was more electropositive than the phenyl radical. 

It has been found68-70 that the reaction of tryptophanase with the inhibitory amino acids, /3-phenyl-DL-serine (threo form), L-threonine and D-alanine, is accompanied by a manifold increase in the reduced LD, i.e. in the ratio of LD to absorbance (AA / A) in the 420-425 nm band (Fig. 9.12 Table 9.2). This band belongs to the protonated internal PLP-lysine... 

APRON 2E APRON FL CG 117 CGA 48988 D,L-N-(2,6-DIMETHYLPHENYL)-N-(2 -METHOXYACET-YL)ALANINATE de METHYLE N-(2,6-DIMETHYL-PHENYL)-N-(METHOXYACETYL)-ALANINE METHYL ESTER N-(2,6-DIMETHYLPHENYL)-N-(METHOXY-ACETYL)-DL-AL, NINE METHYL ESTER METALAXIL... 

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