(S)-2-Amino-5-methoxytetralin (S)-mandelate
[CAS# 439133-67-2]

Identification

• Classification: API >> Nervous system medication >> Antipsychotic
• Name: (S)-2-Amino-5-methoxytetralin (S)-mandelate
• Synonyms: (2S)-2-hydroxy-2-phenylacetic acid;(2S)-5-methoxy-1,2,3,4-tetrahydronaphthalen-2-amine
• Molecular Formula: C₁₁H₁₅NO^.C₈H₈O₃
• Molecular Weight: 329.39
• CAS Registry Number: 439133-67-2
• EC Number: 694-859-4
• SMILES: COC1=CC=CC2=C1CC[C@@H](C2)N.C1=CC=C(C=C1)[C@@H](C(=O)O)O

Properties

• Melting point: 200-201 ºC

Safety Data

• Hazard Symbols: GHS07 Warning
• Hazard Statements: H315-H319-H335
• Precautionary Statements: P261-P264-P264+P265-P271-P280-P302+P352-P304+P340-P305+P351+P338-P319-P321-P332+P317-P337+P317-P362+P364-P403+P233-P405-P501

Discovory and Applicatios

(S)-2-Amino-5-methoxytetralin (S)-mandelate is a chiral organic salt formed by the combination of two optically active components: (S)-2-amino-5-methoxytetralin and (S)-mandelic acid. Each component brings unique stereochemical and pharmacological properties to the compound, which has found relevance in the study of adrenergic receptor ligands and central nervous system pharmacology.

The cationic component, (S)-2-amino-5-methoxytetralin, is a derivative of tetralin (1,2,3,4-tetrahydronaphthalene) bearing an amino group at the 2-position and a methoxy group at the 5-position. The configuration at the 2-position is specifically (S), referring to the absolute stereochemistry. This compound belongs to a class of molecules known for their structural resemblance to catecholamines, and has been explored for its activity as a dopamine receptor agonist. The rigid bicyclic structure imparts conformational constraints that allow selective interaction with receptor subtypes in the brain.

The anionic component, (S)-mandelate, is the conjugate base of (S)-mandelic acid, a naturally occurring alpha-hydroxy acid with a phenyl group. (S)-Mandelic acid has long been used in pharmaceutical synthesis and chiral resolution due to its well-defined stereochemistry and ability to form salts with enantiomerically pure amines.

The formation of the salt between (S)-2-amino-5-methoxytetralin and (S)-mandelic acid serves multiple purposes. It improves the compound's physicochemical properties, such as solubility, stability, and ease of crystallization. In research and pharmaceutical development, creating diastereomeric salts like this one is a common strategy for resolving racemic mixtures of chiral amines. The use of a chiral acid such as (S)-mandelic acid allows the selective crystallization of one enantiomer over the other, facilitating the isolation of optically pure compounds.

Historically, derivatives of 2-amino tetralins have been synthesized and evaluated for their activity on dopaminergic and adrenergic systems. The (S)-enantiomer of 2-amino-5-methoxytetralin in particular has shown agonist activity at dopamine D₂ receptors, which are implicated in numerous neurological and psychiatric conditions. Therefore, the study of its mandelate salt form assists both in purification and in preliminary pharmacological evaluations.

In laboratory settings, the synthesis of this salt involves the neutralization of (S)-2-amino-5-methoxytetralin with equimolar (S)-mandelic acid in a suitable solvent such as ethanol or methanol, followed by crystallization. Characterization is performed using NMR spectroscopy, polarimetry, and X-ray crystallography to confirm both structure and enantiomeric purity.

While the compound is mainly of interest in preclinical and chemical research, its components highlight significant themes in medicinal chemistry, particularly the importance of chirality in drug action and the methods used to resolve and analyze chiral substances. By combining two stereochemically pure components, (S)-2-amino-5-methoxytetralin (S)-mandelate serves as both a functional molecule and a tool in stereochemical investigations.