3,4-Dimethoxyphenethylamine
[CAS# 120-20-7]

Identification

• Classification: Pharmaceutical intermediate >> Heterocyclic compound intermediate >> Pyrimidine compound >> Amine
• Name: 3,4-Dimethoxyphenethylamine
• Synonyms: 2-(3,4-Dimethoxyphenyl)ethylamine; Homoveratrylamine; DMPEA
• Molecular Formula: C₁₀H₁₅NO₂
• Molecular Weight: 181.23
• CAS Registry Number: 120-20-7
• EC Number: 204-376-9
• SMILES: COC1=C(C=C(C=C1)CCN)OC

Properties

• Density: 1.0±0.1 g/cm³ Calc.^*, 1.074 g/mL (Expl.)
• Melting point: 12 - 15 ºC (Expl.)
• Boiling point: 324.1 ºC 760 mmHg (Calc.)^*, 188 ºC (15 mmHg) (Expl.)
• Flash point: 132.8±30.4 ºC (Calc.)^*, 130 ºC (Expl.)
• Solubility: water: soluble (Expl.)
• Index of refraction: 1.518 (Calc.)^*, 1.546 (Expl.)

^* Calculated using Advanced Chemistry Development (ACD/Labs) Software.

Safety Data

• Hazard Symbols: GHS05;GHS07 Danger
• Hazard Statements: H302-H315-H317-H318-H319-H335
• Precautionary Statements: P261-P264-P264+P265-P270-P271-P272-P280-P301+P317-P302+P352-P304+P340-P305+P351+P338-P305+P354+P338-P317-P319-P321-P330-P332+P317-P333+P317-P337+P317-P362+P364-P403+P233-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Acute toxicity	Acute Tox.	4	H302
Skin irritation	Skin Irrit.	2	H315
Serious eye damage	Eye Dam.	1	H318
Skin sensitization	Skin Sens.	1B	H317
Specific target organ toxicity - single exposure	STOT SE	3	H335
Eye irritation	Eye Irrit.	2	H319
Skin corrosion	Skin Corr.	1B	H314
Skin corrosion	Skin Corr.	1C	H314
Acute toxicity	Acute Tox.	4	H332

• Transport Information: UN 2735

Discovory and Applicatios

3,4-Dimethoxyphenethylamine (C₁₀H₁₅NO₂) is an aromatic amine belonging to the phenethylamine class, characterized by a benzene ring bearing two methoxy substituents in the 3 and 4 positions and an ethylamine side chain. The presence of the electron-donating methoxy groups on the aromatic ring significantly influences its chemical reactivity, solubility, and pharmacological profile. It is a structural analog of phenethylamine and part of a larger family of substituted phenethylamines, many of which are biologically active and have been investigated in medicinal chemistry.

The first studies on substituted phenethylamines, including dimethoxy derivatives, can be traced back to the early 20th century, when systematic investigations were carried out to understand the influence of substitution patterns on biological activity. The 3,4-dimethoxy substitution pattern is particularly notable because it is present in a number of naturally occurring and synthetic compounds with pharmacological effects.

Chemically, 3,4-dimethoxyphenethylamine is a basic amine that can form salts with mineral acids such as hydrochloric acid or sulfate, which are more stable and easier to handle than the free base. The compound is soluble in polar solvents and can undergo further transformations, such as N-alkylation or acylation, which lead to derivatives with diverse applications. In laboratory practice, it is sometimes used as a building block in organic synthesis for preparing more complex phenethylamine-based molecules.

From a pharmacological standpoint, substituted phenethylamines with methoxy groups have been widely studied for their interactions with the central nervous system. The 3,4-dimethoxy group plays a role in modulating binding affinity to receptors, influencing both potency and selectivity. While 3,4-dimethoxyphenethylamine itself has been reported as a weakly active compound compared to its more potent analogs, its structural framework has been important in medicinal chemistry for the development of bioactive derivatives.

One of the most notable aspects of 3,4-dimethoxyphenethylamine is its role as a chemical precursor and structural analog in the study of psychoactive substances. Substitution at the amine nitrogen or the introduction of additional groups on the aromatic ring can lead to compounds with stimulant or hallucinogenic activity. Researchers have used 3,4-dimethoxyphenethylamine as a starting point to explore the relationship between chemical structure and neuroactive properties, contributing to the broader understanding of structure–activity relationships within the phenethylamine family.

In addition to its pharmacological significance, the compound has been studied in relation to enzymatic metabolism. Like other substituted phenethylamines, it can undergo oxidative deamination by monoamine oxidases, as well as O-demethylation catalyzed by cytochrome P450 enzymes. These metabolic pathways determine its bioavailability, duration of action, and potential interactions with other substances. The study of its metabolism has helped clarify how methoxy-substituted aromatic amines are processed in biological systems.

Beyond pharmacology, 3,4-dimethoxyphenethylamine has relevance in chemical research, particularly in synthetic organic chemistry. Its electron-rich aromatic ring serves as a useful substrate for electrophilic substitution reactions, while the ethylamine side chain provides opportunities for derivatization into amides, ureas, and other functional groups. This dual reactivity makes it a versatile intermediate for designing both biologically active molecules and functional materials.

In summary, 3,4-dimethoxyphenethylamine is a simple but important member of the substituted phenethylamine family. While it exhibits relatively modest direct biological activity, it has been valuable as a structural analog, a synthetic precursor, and a subject of metabolic and pharmacological studies. Its discovery and continued use in research have provided insight into the chemistry and biology of methoxy-substituted aromatic amines, helping to establish a foundation for the development of more complex and therapeutically relevant compounds.