Home / Products / (R)-2-[[2-(4-Aminophenyl)ethyl]amino]-1-phenylethanol Monohydrochloride
CAS 521284-22-0 Mirabegron Key Intermediate Mirabegron Key Intermediate High Purity USP Grade EP Grade Reference Standard

(R)-2-[[2-(4-Aminophenyl)ethyl]amino]-1-phenylethanol Monohydrochloride

IUPAC: (1R)-2-[2-(4-Aminophenyl)ethylamino]-1-phenylethanol Hydrochloride View on PubChem
CAS NUMBER
521284-22-0
MOL. FORMULA
C16H21ClN2O
MOL. WEIGHT
292.80 g/mol
Scientific Overview

This compound is generated by catalytic transfer hydrogenation (ammonium formate, Pd/C) of the nitro group in the upstream intermediate (Mirabegron Impurity F, CAS 521284-21-9), converting it to the free primary amine, which is then isolated and stabilized as its hydrochloride salt for improved crystallinity and handling. The resulting diaminophenol scaffold --- bearing both a free aniline amine and a chiral secondary amine-alcohol --- provides the two reactive nitrogen sites required for the final coupling step: reaction with 2-(2-aminothiazol-4-yl)acetic acid derivatives installs the thiazolylacetamide moiety that completes mirabegron's structure.

(R)-2-[[2-(4-Aminophenyl)ethyl]amino]-1-phenylethanol monohydrochloride is the hydrochloride salt form of the key diamine intermediate in mirabegron synthesis (free base: CAS 391901-45-4, Mirabegron Impurity 6/M16). It represents the final penultimate building block before thiazole ring coupling completes the mirabegron API structure.

Full Technical Data
Chemical Name (R)-2-[[2-(4-Aminophenyl)ethyl]amino]-1-phenylethanol Monohydrochloride
CAS Number 521284-22-0
IUPAC Name (1R)-2-[2-(4-Aminophenyl)ethylamino]-1-phenylethanol Hydrochloride
Molecular Formula C16H21ClN2O
Molecular Weight 292.80 g/mol g/mol
Reaction Scheme
(R)-2-((4-Nitrophenethyl)amino)-1-phenylethanol Hydrochloride (Mirabegron Impurity F)
NA
NA
(R)-2-[[2-(4-Aminophenyl)ethyl]amino]-1-phenylethanol Monohydrochloride
NA
Commercial Applications

Mirabegron API Manufacturing

Final key intermediate before thiazole coupling completes the mirabegron drug substance structure.

Pharmacopeial Reference Standard

Supports quality control testing across mirabegron manufacturing quality programs.

Regulatory Submission Support

Used in ANDA/NDA filings requiring characterized advanced intermediate reference materials.

API Process Chemistry

Central to route scale-up and process validation for commercial mirabegron production.

Market Therapeutic Focus
MIRABEGRON KEY INTERMEDIATE PHARMACEUTICAL MANUFACTURING UROLOGY / OVERACTIVE BLADDER THERAPEUTICS ANALYTICAL REFERENCE STANDARDS API PROCESS CHEMISTRY CRO/CDMO
Scientific Literature

Mirabegron: A Review of its Use in Overactive Bladder Syndrome

Authors: Cui, Y. et al.

Drugs

Synthesis and Structure-Activity Relationships of ß3-Adrenergic Receptor Agonists

Authors: Ohtake, Y. et al.

J. Med. Chem.

Process Development and Impurity Control for Mirabegron API Manufacturing

Authors: Various

Org. Process Res. Dev. (process chemistry reference)

Peer Queries & FAQs
How does this compound complete the mirabegron synthesis?
Its free primary amine (aniline nitrogen) reacts with a thiazolylacetic acid derivative in the final coupling step, installing the thiazolylacetamide group that defines mirabegron's complete pharmacophore.
Why is this offered as both a free base and hydrochloride salt?
The hydrochloride salt (this product) generally offers better crystallinity, stability, and handling properties for process chemistry and reference standard applications compared to the free base (CAS 391901-45-4).
Is this compound itself pharmacologically active?
No --- it's a synthetic intermediate lacking the thiazolylacetamide pharmacophore required for ß3-adrenergic receptor activity; it must be coupled with the thiazole fragment to become active mirabegron.
What is the recommended storage condition?
Store in a tightly sealed container at 0--8°C (refrigerated), protected from light and moisture.

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