(S)-(+)-2-Aminooctane: Handling & Application Protocol

(S)-(+)-2-Aminooctane is a chiral, enantiomerically enriched primary amine widely employed as a versatile building block and resolving agent in asymmetric synthesis and pharmaceutical research.

Chemical Name

(S)-(+)-2-Aminooctane

SKU

S657055

Compound Class

Chiral primary amine

Stereochemistry

(S)-configuration, optically active (+)

Molecular Formula

C8H19N

Molecular Weight

129.25 g/mol

CAS Number

6168-72-5

Materials & Safety Precautions

(S)-(+)-2-Aminooctane (SKU: S657055) is a flammable liquid amine and should be handled with appropriate personal protective equipment (PPE), including chemical-resistant gloves, safety goggles, and a lab coat. Work should be conducted in a well-ventilated fume hood to avoid inhalation of vapors.

Store the compound in a tightly sealed container under an inert atmosphere (nitrogen or argon) at 2–8 °C or as specified on the product label. Keep away from strong acids, oxidizers, and ignition sources. Consult the Safety Data Sheet (SDS) prior to use for full hazard information, first-aid measures, and disposal guidelines.

Required materials:

• (S)-(+)-2-Aminooctane (S657055)
• Anhydrous organic solvent (e.g., dichloromethane, THF, or toluene) as appropriate for the reaction
• Inert gas supply (N₂ or Ar)
• Molecular sieves (3 Å or 4 Å) for moisture-sensitive reactions
• Analytical balance, syringes, and Schlenk glassware as needed
• Chiral HPLC or polarimetry equipment for enantiomeric excess (ee) verification

Sample Preparation & Quantification

Before use, verify the optical purity of (S)-(+)-2-Aminooctane by measuring the optical rotation using a polarimeter. The specific optical rotation [α]D should be positive (+) for the (S)-enantiomer; confirm against the certificate of analysis (CoA) supplied with the product.

Preparation steps:

1. Allow the sealed vial to equilibrate to room temperature before opening to prevent condensation of atmospheric moisture.
2. Under an inert atmosphere, transfer the required volume of (S)-(+)-2-Aminooctane using a dry syringe or cannula.
3. Prepare stock solutions in anhydrous solvent at the desired concentration (typical range: 0.1–1.0 M for synthetic applications).
4. For gravimetric measurement, tare the receiving vessel and add the neat liquid carefully; record the mass and calculate moles using MW = 129.25 g/mol.
5. If moisture-sensitive downstream chemistry is planned, dry the solvent over activated molecular sieves for at least 24 hours prior to use.

Confirm enantiomeric excess (ee) by chiral HPLC if required by the experimental design, using a suitable chiral stationary phase column compatible with primary aliphatic amines.

Protocol: Applications in Asymmetric Synthesis & Chiral Resolution

(S)-(+)-2-Aminooctane serves several roles in synthetic chemistry. The two primary applications are outlined below.

A. Chiral Resolution of Racemic Acids

1. Dissolve the racemic carboxylic acid (1.0 equiv) in a suitable solvent (e.g., ethanol or isopropanol).
2. Add (S)-(+)-2-Aminooctane (1.0–1.05 equiv) dropwise with stirring at room temperature to form diastereomeric salts.
3. Allow crystallization by cooling the solution slowly to 0–5 °C or by slow evaporation.
4. Collect the precipitated diastereomeric salt by vacuum filtration and wash with cold solvent.
5. Liberate the resolved acid by treating the salt with dilute aqueous base (e.g., NaOH, 1 M), followed by acidification and extraction.
6. Measure optical rotation or ee by chiral HPLC to assess the resolution efficiency.

B. Chiral Amine Building Block in Amide/Imine Formation

1. Charge a dry round-bottom flask with the acylating agent or carbonyl compound (1.0 equiv) in anhydrous solvent under N₂.
2. Add (S)-(+)-2-Aminooctane (1.0–1.2 equiv) and a base (e.g., triethylamine, 1.2 equiv) if required to neutralize the byproduct acid.
3. Stir at room temperature or at the temperature specified by the reaction conditions, monitoring by TLC or HPLC.
4. Upon completion, work up the reaction by washing with aqueous base and brine, then dry the organic layer over anhydrous MgSO₄ or Na₂SO₄.
5. Remove solvent under reduced pressure and purify the product by column chromatography or recrystallization.
6. Characterize the product by NMR, optical rotation, and chiral HPLC as appropriate.

Results Interpretation & Troubleshooting

Expected outcomes: Successful chiral resolution should yield diastereomeric salts with clearly distinct solubility profiles. Liberated acid fractions should display measurable optical rotation and ee values typically >80% after a single resolution step, with further improvement possible upon recrystallization.

Troubleshooting guide:

Problem	Likely Cause	Suggested Action
Low ee in resolved product	Insufficient diastereomeric salt discrimination	Optimize solvent, temperature, or stoichiometry; repeat recrystallization
No precipitate forms	Solvent polarity too high or temperature too warm	Switch to less polar solvent; cool to lower temperature
Racemization observed	Harsh acidic/basic conditions during liberation step	Use milder pH conditions and lower temperatures
Low yield of amide product	Incomplete coupling or side reactions	Ensure anhydrous conditions; check reagent quality; optimize base equivalents

Always confirm product identity and stereochemical integrity by NMR spectroscopy and chiral HPLC before proceeding to downstream applications.

Storage, Disposal & Quality Notes

Storage: Store (S)-(+)-2-Aminooctane in a tightly sealed container under an inert gas blanket (N₂ or Ar) at 2–8 °C, protected from light and moisture. Avoid repeated freeze-thaw cycles. Check the product CoA upon receipt to confirm optical purity and specification compliance before committing to large-scale experiments.

Disposal: Dispose of (S)-(+)-2-Aminooctane and solvent waste in accordance with local, regional, and national regulations for flammable amine-containing waste. Do not pour down the drain. Use dedicated labeled waste containers and coordinate with your institution's environmental health and safety (EHS) office.

Quality assurance: Aladdin Scientific provides a Certificate of Analysis (CoA) for each lot of S657055. Verify the following key parameters on receipt: identity (GC or NMR), purity (GC %), and optical rotation [α]D. If any parameter falls outside specification, contact Aladdin Scientific customer service for support or replacement.

Frequently asked questions

What is (S)-(+)-2-Aminooctane used for in the laboratory?

(S)-(+)-2-Aminooctane is primarily used as a chiral resolving agent for racemic carboxylic acids via diastereomeric salt formation, and as an enantiomerically pure building block for the synthesis of chiral amides, imines, and other nitrogen-containing derivatives in asymmetric synthesis programs.

How should I verify the enantiomeric purity of (S)-(+)-2-Aminooctane before use?

Optical purity can be confirmed by measuring the specific optical rotation [α]D with a polarimeter and comparing the result to the value stated on the Certificate of Analysis (CoA). For more precise quantification, chiral HPLC using an appropriate chiral stationary phase column is recommended to determine the enantiomeric excess (ee) directly.

What solvents are compatible with (S)-(+)-2-Aminooctane for synthetic applications?

Common compatible solvents include dichloromethane, tetrahydrofuran (THF), toluene, ethanol, and isopropanol. The choice of solvent depends on the specific reaction or resolution application. For moisture-sensitive reactions, anhydrous solvents dried over molecular sieves should be used. Protic solvents such as ethanol are preferred for diastereomeric salt crystallization.

How should (S)-(+)-2-Aminooctane be stored to maintain its optical purity?

The compound should be stored in a tightly sealed container under an inert atmosphere (nitrogen or argon) at 2–8 °C, protected from light and moisture. Exposure to air, moisture, or elevated temperatures should be minimized to prevent degradation or racemization over time.

References

1. Eliel, E. L.; Wilen, S. H. Stereochemistry of Organic Compounds. Wiley-Interscience, New York, 1994.
2. Jacques, J.; Collet, A.; Wilen, S. H. Enantiomers, Racemates, and Resolutions. Wiley, New York, 1981.
3. Aladdin Scientific Certificate of Analysis, (S)-(+)-2-Aminooctane, SKU S657055. Aladdin Scientific, Shanghai.

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