(S)-(+)-2-Aminooctane: Properties, Uses & Lab Guide

(S)-(+)-2-Aminooctane is an enantiopure chiral primary amine valued in asymmetric synthesis, chiral resolution, and as a stereochemical reference standard due to its well-defined (S)-configuration and positive optical rotation.

Chemical Name

(S)-(+)-2-Aminooctane

Molecular Formula

C₈H₁₉N

Molecular Weight

129.25 g/mol

Stereochemistry

(S)-configuration; positive optical rotation ([α]D > 0)

Compound Class

Chiral primary aliphatic amine

CAS Number

6850-57-3

Key Application

Asymmetric synthesis, chiral resolution, reference standard

Chemical Identity and Stereochemistry

(S)-(+)-2-Aminooctane (CAS 6850-57-3) is a straight-chain aliphatic primary amine with the molecular formula C₈H₁₉N and a molecular weight of approximately 129.25 g/mol. The compound features a single stereogenic carbon at the C-2 position, bearing an amino group (–NH₂), a methyl group, a hydrogen atom, and a hexyl chain. The (S)-descriptor refers to the absolute configuration assigned by the Cahn–Ingold–Prelog (CIP) priority rules, while the (+) sign denotes a positive (dextrorotatory) optical rotation measured in standard conditions.

The chirality of 2-aminooctane makes it a member of the broader family of chiral aliphatic amines, which are important building blocks and resolving agents in stereochemical research. The enantiomeric counterpart, (R)-(–)-2-aminooctane, exhibits an equal but opposite optical rotation. High enantiomeric excess (ee) is a critical quality parameter for this reagent, and researchers should verify the ee value from the certificate of analysis (CoA) before use in stereospecific applications.

Physical and Chemical Properties

(S)-(+)-2-Aminooctane is a colorless to pale yellow liquid at room temperature with a characteristic amine odor. As a primary aliphatic amine, it is moderately basic (pKa of the conjugate acid is expected in the range typical of aliphatic amines, approximately 10–11), readily forming salts with mineral and organic acids. It is miscible with common organic solvents such as ethanol, diethyl ether, dichloromethane, and chloroform, and has limited miscibility with water due to its relatively long hydrophobic octyl backbone.

The compound is sensitive to air oxidation and prolonged exposure to moisture may promote gradual degradation or carbamation. For long-term storage, it is recommended to keep the reagent under an inert atmosphere (argon or nitrogen), sealed tightly, and stored at 2–8 °C or as indicated on the product label. These precautions help maintain optical purity and chemical integrity over time.

Research Applications

Asymmetric Synthesis: Enantiopure primary amines such as (S)-(+)-2-aminooctane serve as chiral auxiliaries, ligands, or nitrogen nucleophiles in asymmetric transformations. They can be incorporated into chiral catalysts or used to introduce a stereodefined nitrogen center into target molecules, enabling the construction of complex chiral pharmaceuticals, agrochemicals, and natural product analogs.

Chiral Resolution: (S)-(+)-2-Aminooctane is employed as a resolving agent for the separation of racemic acids into their enantiomers via diastereomeric salt formation. The amine reacts with a racemic carboxylic acid to give two diastereomeric ammonium salts that differ in physical properties (e.g., solubility, melting point) and can be separated by fractional crystallization.

Reference Standard and Analytical Chemistry: High-purity, enantiopure 2-aminooctane is used as a reference compound in polarimetry, chiral HPLC method development, and NMR studies of chiral discrimination. It also serves as a model substrate for evaluating the enantioselectivity of new catalytic systems or enzymes in academic and industrial research settings.

Safe Handling and Regulatory Considerations

(S)-(+)-2-Aminooctane is a flammable liquid and a corrosive/irritant amine. Standard laboratory safety precautions apply: work in a well-ventilated fume hood, wear appropriate personal protective equipment (PPE) including chemical-resistant gloves, lab coat, and safety goggles. Avoid inhalation of vapors and direct skin or eye contact, as primary aliphatic amines can cause irritation or chemical burns.

Waste disposal must comply with local and national regulations governing flammable and amine-containing chemical waste. Consult the Safety Data Sheet (SDS) provided by Aladdin Scientific before use. Keep away from strong oxidizers, strong acids, and ignition sources. Emergency procedures for spills should follow the SDS guidance, including the use of appropriate absorbents and neutralization protocols.

Purchasing and Quality Assurance

Aladdin Scientific offers (S)-(+)-2-Aminooctane (SKU: S657055) with documented purity and enantiomeric excess provided in the certificate of analysis (CoA). When sourcing chiral amine reagents, researchers and procurement personnel should confirm the following quality parameters: chemical purity (GC or HPLC), enantiomeric excess (chiral HPLC or polarimetry), and lot-specific optical rotation data.

Proper lot traceability is essential for reproducible results in asymmetric synthesis and regulatory submissions. Aladdin Scientific maintains rigorous quality control procedures to ensure batch-to-batch consistency. For large-scale or GMP-aligned procurement needs, contact Aladdin's technical sales team to discuss custom packaging, bulk quantities, and additional documentation requirements.

Frequently asked questions

What is the difference between (S)-(+)-2-aminooctane and (R)-(-)-2-aminooctane?

The two compounds are enantiomers: they share the same molecular formula and connectivity but have opposite absolute configurations at C-2. (S)-(+)-2-Aminooctane rotates plane-polarized light to the right (dextrorotatory), while the (R)-(–) enantiomer rotates it to the left. In achiral environments they exhibit identical physical properties except optical rotation, but they behave differently in chiral or biological contexts.

How should (S)-(+)-2-aminooctane be stored to maintain enantiopurity?

Store the reagent in a tightly sealed container under an inert atmosphere (nitrogen or argon) at 2–8 °C, away from light, moisture, and oxidizing agents. Aliphatic amines can absorb CO₂ from air to form carbamates, which may affect purity; therefore, minimize headspace and use appropriate septum-sealed vials for repeated sampling. Always verify optical rotation and ee before critical experiments.

Can (S)-(+)-2-aminooctane be used as a resolving agent for racemic acids?

Yes. (S)-(+)-2-Aminooctane reacts with racemic carboxylic acids to form pairs of diastereomeric ammonium salts, which can often be separated by fractional crystallization or other physical methods. After separation, the free acid enantiomers are recovered by treatment with a stronger base. The resolving power depends on the structural match between the amine and the target acid, so preliminary small-scale trials are recommended.

What analytical methods are used to verify the enantiomeric excess of 2-aminooctane?

Enantiomeric excess is typically determined by chiral stationary-phase HPLC using a suitable chiral column, or by polarimetry by comparing the measured specific optical rotation against the known value for the pure enantiomer. Derivatization with chiral acylating agents followed by achiral GC or HPLC can also be employed. All three approaches are complementary, and the method chosen should match the sensitivity and throughput requirements of the application.

Is (S)-(+)-2-aminooctane suitable for use as a chiral ligand precursor?

(S)-(+)-2-Aminooctane can serve as a building block for the synthesis of chiral ligands, particularly those incorporating secondary or tertiary amine donors, Schiff base frameworks, or chiral diamine architectures. The primary amine functionality allows straightforward condensation with aldehydes or ketones to form imines, which can be further elaborated into ligands for asymmetric metal catalysis. Suitability depends on the specific ligand design and compatibility with subsequent synthetic steps.

References

1. Eliel, E. L.; Wilen, S. H. Stereochemistry of Organic Compounds. Wiley-Interscience, 1994.
2. Jacques, J.; Collet, A.; Wilen, S. H. Enantiomers, Racemates and Resolutions. Wiley, 1981.
3. Clayden, J.; Greeves, N.; Warren, S. Organic Chemistry, 2nd ed. Oxford University Press, 2012.

Products are supplied for research and development use only. Not for use in humans, animals, diagnosis, or therapy.