A nitro group can be introduced on an active carbon atom by a Claisen-type reaction with an alkyl nitrate. "Organic Syntheses" describes the preparation of methyl nitrate. I have not tried it, but suggest anyone who does ought to take the precaution of adding urea to the nitric acid mixture; and not make any more than is required for the next job. Gattermann ."Laboratory Methods of Organic Chemistry" describes the preparation of ethyl nitrate. This is a commercially available material, used as an additive to raise the cetane number of diesel fuels.
Both "Organic Syntheses" and Gattermann describe the use of these reagents to nitrate phenylacetonitrile to form sodium phenylacinitroacetonitrile, with a view to hydrolysis and decarboxylation to give phenylnitromethane. The reaction conditions are typical: sodium ethoxide in ethanol solution. A literature search would no doubt turn up other examples.
The implication is that a phenylethylamine could be produced by substitution of malonic ester with the appropriate benzyl chloride analogue, nitration, hydrolysis, and reduction of the resulting nitro compound.
The nitrate esters are of course potentially explosive materials. Admittedly, only someone properly qualified, who knows the hazards of the materials involved, should actually do synthetic organic chemistry. However, this particular risk can be avoided by resorting to a standard method for synthesizing amino acids. Diethyl malonate with sodium nitrite in an acid medium gives oximinomalonic ester, which is reduced with zinc dust in acetic acid to acetylaminomalonic ester. This can be substituted in the usual way with the benzyl chloride analogue. Hydrolysis will give the phenylalanine analogue of the phenylethylamine. Amionacids are decarboxylated in a high-boiling solvent, with a suitable catalyst. Rhodium gives the procedure for tryptophan, but it is general. A reference that is to hand is: Takano, S., Nishimura, T. & Ogasawara, K. (1977). Efficient synthesis of tryptamine. Heterocycles, 6(
, 1167-1171.
Other method for synthesizing amino acids could be adaptable. Is there any information on psychoactive effects of amino acid analogues of phenylethylamines? One, methyl-DOPA (Aldomet) is used as an anti-hypertensive agent.
One other question: Are there not ways of substituting an aminoacid on the alpha-carbon atom?