2-Amino-3-hydroxy-5-bromopyridine
[CAS# 39903-01-0]

Identification

• Classification: Pharmaceutical intermediate >> Heterocyclic compound intermediate >> Pyridine compound >> Hydroxypyridine
• Name: 2-Amino-3-hydroxy-5-bromopyridine
• Synonyms: 2-Amino-5-bromo-3-hydroxypyridine; 2-Amino-5-bromo-3-pyridinol; 5-Bromo-3-hydroxy-2-aminopyridine
• Molecular Formula: C₅H₅BrN₂O
• Molecular Weight: 189.01
• CAS Registry Number: 39903-01-0
• EC Number: 689-734-6
• SMILES: C1=C(C=NC(=C1O)N)Br

Properties

• Density: 1.9±0.1 g/cm³ Calc.^*
• Melting point: 204-207 °C
• Boiling point: 368.7±42.0 °C 760 mmHg (Calc.)^*
• Flash point: 176.8±27.9 °C (Calc.)^*
• Index of refraction: 1.692 (Calc.)^*

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

Safety Data

• Hazard Symbols: GHS07 Warning
• Risk Statements: H302-H312-H317-H332
• Safety Statements: P261-P264-P270-P271-P272-P280-P301+P317-P302+P352-P304+P340-P317-P321-P330-P333+P317-P362+P364-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Skin sensitization	Skin Sens.	1	H317
Acute toxicity	Acute Tox.	4	H332
Acute toxicity	Acute Tox.	4	H312
Acute toxicity	Acute Tox.	4	H302
Skin irritation	Skin Irrit.	2	H315
Eye irritation	Eye Irrit.	2	H319

Discovery and Applications

2‑Amino‑3‑hydroxy‑5‑bromopyridine (CAS 39903‑01‑0) is a multifunctional pyridine derivative. Its molecular formula is C₅H₅BrN₂O, and it has a molecular weight of approximately 189.01 g/mol. Structurally, the compound features a pyridine ring substituted at the 2‑position with an amino group (–NH₂), a hydroxyl group (–OH) at the 3‑position, and a bromine atom at the 5‑position. This arrangement provides a combination of nucleophilic (amino and hydroxyl) and electrophilic (bromo) functionalities, making it a flexible intermediate in organic synthesis.

The compound is primarily used as a synthetic intermediate. The bromine atom at the 5‑position is especially useful for cross‑coupling reactions (e.g., Suzuki, Buchwald–Hartwig) to install various substituents or to extend the pyridine scaffold. Meanwhile, the amino and hydroxyl groups enable further derivatization through acylation, alkylation, or condensation reactions. These functional groups also contribute to potential coordination with metal centers, meaning the molecule can serve as a ligand in coordination chemistry.

In medicinal chemistry, derivatives built on the 2‑amino-3-hydroxy‑5‑bromopyridine scaffold are of interest because aminopyridines and hydroxypyridines are known bioactive motifs. The combination of these groups with the bromine substituent makes this compound valuable for the development of heterocyclic libraries. Such derivatives may be explored for enzyme inhibition, antibacterial activity, or other pharmacological properties, although specific biological activity data for this exact compound are limited.

In practical synthesis, 2‑Amino‑3‑hydroxy‑5‑bromopyridine can be prepared from more complex precursors. One reported procedure (via chemical‑supplier documentation) starts from 6‑bromo‑3H‑oxazolo[4,5‑b]pyridin‑2‑one, which is reacted under strongly basic conditions (e.g., 2N NaOH) with reflux to yield the amino-hydroxypyridine after neutralization and isolation. The high yield and straightforward procedure make it attractive for scale-up as a building block.

Handling this compound in the laboratory requires standard precautions. The primary amine makes it somewhat reactive toward acylating agents, and the brominated heterocycle can undergo unwanted side reactions if exposed to strong nucleophiles. It should be stored in a dry, inert atmosphere, and reactions often use aprotic, polar solvents to ensure solubility and minimize side reactions.

Despite its utility as a synthetic intermediate, peer-reviewed academic literature specifically focused on 2‑Amino-3-hydroxy-5-bromopyridine is scarce. Most of the available information comes from catalog listings and databases that describe it as a chemical building block rather than a final active pharmaceutical or biological agent.

References

Douangamath A, Fearon D, Gehrtz P, et al. (2023) Open science discovery of potent noncovalent SARS-CoV-2 main protease inhibitors. Science (New York, N.Y.) 382 6591 469–474 DOI: 10.1126/science.abo7201

Kolotova E, Lapin I, Morozova O, et al. (2020) Synthesis and Anticancer Activity of 1,3,4-Oxadiazole-oxazolo[4,5-b]pyridine Derivatives. Russian Journal of General Chemistry 90 7 1235–1243 DOI: 10.1134/s107036322007021x

Fang Y, Li H, Liu Y, et al. (2011) 5-Bromo-3-(indan-1-yl-oxy)pyridin-2-amine. Acta crystallographica. Section E, Structure reports online 67 2 o351–o352 DOI: 10.1107/s1600536811005332