Drugs & Medication

Phenethylamine [1]
Chemical name	2-Phenylethylamine
Other names	Phenethylamine β-Phenylethylamine 2-Phenyl-1-aminoethane β-Aminoethylamine 2-Phenylethanamine
Chemical formula	C8H11N
Molecular mass	121.18 g/mol
CAS number	[64-04-0]
Density	0.964 g/cm3
Melting point	-60 °C
Boiling point	194.5-195 °C
SMILES	c1ccccc1CCN
NFPA 704	2 2 2

Phenethylamine, or β-Phenylethylamine, is an alkaloid and monoamine. In the human brain, it is believed to function as a neuromodulator or neurotransmitter (trace amine). Phenethylamine is a natural compound biosynthesized from the amino acid phenylalanine by enzymatic decarboxylation. It is also found in many foods such as chocolate, especially after microbial fermentation. It has been suggested that phenethylamine from food may have psychoactive effects in sufficient quantities. However, it is quickly metabolized by the enzyme MAO-B, preventing significant concentrations from reaching the brain.

Substituted phenethylamines are a broad and diverse class of compounds that include neurotransmitters, hormones, stimulants, hallucinogens, entactogens, anorectics, bronchodilators, and antidepressants. The phenethylamine structure can also be found as part of more complex ring systems such as the ergoline system of LSD or the morphinan system of morphine.

Contents 1 Chemistry 2 Substituted phenethylamines 3 Pharmacology 4 References 5 External links

Chemistry

Phenethylamine is an aromatic amine which is a colorless liquid at room temperature. It is soluble in water, ethanol, and ether.^[1] Similar to other low molecular weight amines, it has a fishy odor. Upon exposure to air, it forms a solid carbonate salt with carbon dioxide. Phenethylamine is strongly basic and forms a stable crystalline hydrochloride salt with a melting point of 217 °C. Phenethylamine is also a skin irritant and possible sensitizer.

Substituted phenethylamines

Substituted phenethylamines carry additional chemical modifications at the phenyl ring, the sidechain, or the amino group:

• Amphetamines are homologues of phenethylamines carrying an alpha-methyl (α-CH3) group at the sidechain carbon atom next to the amino group.
• Catecholamines are phenethylamines carrying two hydroxy groups in positions 3 and 4 of the phenyl ring. Examples are the hormones and neurotransmitters dopamine, epinephrine (adrenaline), and norepinephrine (noradrenaline).
• The aromatic amino acids phenylalanine and tyrosine are phenethylamines carrying a carboxyl group (COOH) in alpha position.

Pharmacology

Many substituted phenethylamines are pharmacologically active drugs due to their similarity to the monoamine neurotransmitters:

• Stimulants like the plant alkaloids ephedrine and cathinone and the synthetic drugs amphetamine (speed, benzedrine) and methylphenidate
• Hallucinogens like the plant alkaloid mescaline and the synthetic drug 2C-B
• Empathogen-entactogens like MDMA (ecstasy) and MDA
• Anorectics like phentermine, fenfluramine, and amphetamine
• Bronchodilators like salbutamol and ephedrine
• Antidepressants like bupropion and the monoamine oxidase inhibitors phenelzine and tranylcypromine.

References

1. ^ ^a b Merck Index, 12th Edition, 7371.

External links

• MSDS for phenethylamine
• Book II of PiHKAL online
• Review and summary of PiHKAL, including table of 300+ phenethylamines: ascii postscript
• A Structural Tour of PiHKAL