Chemical Identity and Structure

tert-Butyl (3-amino-2,6-difluorophenyl)carbamate (CAS lookup recommended; SKU T734784) is an aromatic compound bearing two distinct nitrogen functionalities on the same ring: a free primary amine at the 3-position and a tert-butoxycarbonyl (Boc)-protected amine at the 1-position. The two fluorine atoms at the 2- and 6-positions create significant steric and electronic effects, inductively withdrawing electron density from the ring while imposing conformational constraints on substituents at the 1-position carbamate nitrogen.

The molecular formula is C₁₁H₁₄F₂N₂O₂ with a molecular weight of approximately 244.24 g/mol. The presence of geminal ortho-fluorines is a hallmark motif in modern drug design, conferring improved metabolic stability, altered lipophilicity (lipophilic fluorine effect), and restricted rotation compared to non-fluorinated analogues. The free amine provides a handle for further functionalization, including acylation, sulfonylation, reductive amination, and coupling reactions.

Synthetic Utility and Applications

This compound serves as a bifunctional building block in multi-step synthesis. The orthogonal protecting group strategy—using the Boc group to mask one amine while the free amine participates in selective transformations—makes it particularly valuable in library synthesis and iterative coupling campaigns.

Typical applications include:

• Heterocyclic synthesis: Cyclization of the free amine with electrophilic partners (aldehydes, ketones, acyl chlorides, isocyanates) to form benzimidazoles, benzoxazoles, quinazolines, or urea-linked scaffolds relevant to kinase inhibitor and GPCR ligand programs.
• Amide and sulfonamide formation: The primary amine can be acylated or sulfonylated selectively prior to Boc deprotection, enabling sequential functionalization.
• Boc deprotection and downstream elaboration: Treatment with trifluoroacetic acid (TFA) in dichloromethane (DCM) or 4 M HCl in 1,4-dioxane removes the Boc protecting group to unmask the second amine for further coupling reactions.
• Cross-coupling reactions: After conversion of the free amine to a diazonium salt or aryl halide equivalent, palladium-catalyzed cross-coupling reactions (Suzuki, Buchwald–Hartwig) can be employed.

The ortho-difluoro substitution pattern is particularly useful in programs targeting fluorinated analogues for improved CNS penetration or metabolic blocking of oxidative soft spots.

Handling, Safety, and Storage Guidelines

As with all research-grade organic intermediates containing aromatic amines, appropriate laboratory safety practices must be observed when handling tert-Butyl (3-amino-2,6-difluorophenyl)carbamate.

Personal Protective Equipment (PPE): Wear chemical-resistant gloves (nitrile recommended), a laboratory coat, and safety glasses or a face shield. For operations generating dust or aerosols, use a respirator rated for organic particulates.

Ventilation: Handle in a fume hood or well-ventilated enclosure. Aromatic amines may pose inhalation hazards; avoid breathing dust or vapors.

Storage: Store the compound in a tightly sealed container in a cool (2–8 °C or ambient as specified in the product SDS), dry location away from direct light, oxidizing agents, and strong acids. The Boc group is susceptible to hydrolysis under acidic or prolonged moist conditions; moisture exclusion is recommended for long-term storage.

Disposal: Dispose of residues and contaminated materials in accordance with local, national, and institutional regulations for hazardous organic waste. Do not pour down the drain without verification of local regulations.

Spill Response: Collect solid spills with a non-sparking scoop; transfer to a labeled waste container. For large spills, evacuate and ventilate the area and consult the SDS.

Note: Always consult the current Safety Data Sheet (SDS) provided by Aladdin Scientific for definitive hazard, first-aid, and disposal information prior to use.

Quality, Purity, and Analytical Considerations

For reproducible results in synthetic workflows, the purity and integrity of tert-Butyl (3-amino-2,6-difluorophenyl)carbamate should be assessed before use, particularly for sensitive reactions or biological assays.

Recommended Analytical Methods:

• ¹H and ¹³C NMR: Confirm structure and assess purity. Key signals include the Boc tert-butyl singlet (~1.50 ppm, 9H), aromatic protons, and the NH protons. ¹⁹F NMR can confirm the presence and chemical equivalence/inequivalence of the two fluorine atoms.
• HPLC: Reverse-phase HPLC (C18 column, UV detection at 254 nm or 280 nm) provides quantitative purity assessment. A purity of ≥95% is generally required for synthetic applications.
• LC-MS: Electrospray ionization (ESI) mass spectrometry confirms molecular identity. Expected [M+H]⁺ at m/z ≈ 245.10 (verify against exact mass calculation).
• Melting Point: Can serve as an identity check; compare against literature or certificate of analysis (CoA) values.

The free amine group may be prone to oxidation or reaction with atmospheric CO₂ under extended exposure; check for discoloration or changes in solubility as indicators of degradation. Refer to the Aladdin Scientific Certificate of Analysis (CoA) for lot-specific purity data.