Chemical Identity and Physical Properties

1-Bromo-4-(trimethylsilyl)but-3-yn-2-one (CAS number should be confirmed with the supplier's CoA) is a compact, bifunctional molecule with the molecular formula C₇H₁₁BrOSi. Its structure integrates three distinct reactive handles on a linear four-carbon backbone: (1) a primary C–Br bond at the α-position of the carbonyl, making it a potent electrophile toward nucleophiles such as amines, thiols, and enolates; (2) a ketone carbonyl susceptible to condensation and addition reactions; and (3) a trimethylsilyl (TMS)-capped alkyne that can be deprotected to reveal a terminal alkyne for click chemistry, Sonogashira couplings, or cyclization reactions.

The TMS group confers improved bench stability relative to the parent terminal alkyne, reducing unwanted oxidative dimerization (Glaser coupling) during handling and purification. The compound is expected to be a pale to colorless liquid or low-melting solid; exact physical constants (boiling point, melting point, density) should be verified against the supplier's Certificate of Analysis (CoA) for lot-specific data.

Synthetic Applications and Reactivity

The dual electrophilic–alkyne character of 1-Bromo-4-(trimethylsilyl)but-3-yn-2-one makes it a versatile building block in heterocyclic synthesis, natural product total synthesis, and the preparation of π-conjugated materials.

• α-Alkylation and N/O/S-Alkylation: The activated C–Br bond undergoes facile S_N2 displacement with soft nucleophiles (thiolates, imidazoles, indoles) under mild conditions, often at room temperature in polar aprotic solvents such as DMF or acetonitrile.
• Sonogashira Cross-Coupling: After fluoride-mediated TMS deprotection (e.g., K₂CO₃/MeOH or TBAF/THF), the liberated terminal alkyne participates in Pd/Cu-catalyzed Sonogashira couplings with aryl and vinyl halides, expanding molecular complexity.
• Cyclization Chemistry: The 1,3-relationship between the bromine and the ynone system enables intramolecular and intermolecular annulation reactions with bifunctional nucleophiles (e.g., amino-thiols, hydrazines) to furnish five- and six-membered heterocycles including pyrazoles, isoxazoles, and thiophenes.
• Click Chemistry: Following TMS removal, the terminal alkyne can engage in copper-catalyzed azide–alkyne cycloaddition (CuAAC) for bioconjugation and library synthesis.

Reaction optimization should be performed at small scale first due to the electrophilic sensitivity of the molecule. Reactions involving the α-bromoketone moiety may generate HBr as a byproduct; use of a base (e.g., Et₃N, K₂CO₃) is recommended to neutralize acid and prevent substrate decomposition.

Safe Handling, Storage, and Disposal

Hazard Profile: As an α-bromoketone, 1-Bromo-4-(trimethylsilyl)but-3-yn-2-one is expected to be a lachrymatory irritant and a tissue-corrosive electrophile. Researchers should treat it with the precautions appropriate for reactive alkyl halides. Always consult the supplier's Safety Data Sheet (SDS) before use; the SDS for B589116 should be obtained from Aladdin Scientific prior to handling.

Personal Protective Equipment (PPE): Wear chemically resistant nitrile or neoprene gloves, safety glasses or face shield, and a laboratory coat. Work inside a certified chemical fume hood at all times. For extended handling or larger quantities, a half-face respirator with organic vapor cartridges is recommended.

Storage: Store in a tightly sealed container under an inert atmosphere (N₂ or Ar) at 2–8 °C or as specified on the CoA. Keep away from moisture, light, heat sources, and incompatible materials including strong bases, strong oxidizers, and nucleophilic solvents (e.g., methanol, water) that may trigger premature reaction.

Disposal: Dispose of waste material in accordance with local, national, and institutional regulations for halogenated organic waste. Do not pour down the drain. Neutralize small spills with dilute sodium bicarbonate solution before absorbing with inert material and placing in labeled hazardous waste containers.

Quality, Purity, and Verification

Aladdin Scientific supplies 1-Bromo-4-(trimethylsilyl)but-3-yn-2-one under SKU B589116. Each lot is accompanied by a Certificate of Analysis (CoA) detailing purity (typically assessed by GC or HPLC), identity confirmation (NMR or MS), and lot-specific physical data. Researchers should verify the following upon receipt:

• Identity: Confirm by ¹H NMR. Characteristic signals include the methylene protons of the bromoacetyl group (–COCH₂Br, approximately δ 3.8–4.0 ppm in CDCl₃) and the TMS group singlet (approximately δ 0.2 ppm, 9H). Exact chemical shift values should be confirmed against literature or the CoA.
• Purity: GC purity ≥95% is typical for research-grade material; confirm the specification on the CoA.
• Appearance: Visually inspect for unusual color (yellowing or browning may indicate partial decomposition) or precipitation.
• Moisture sensitivity check: The compound should be handled with Schlenk or glovebox techniques if stored material shows evidence of moisture ingress.

If quality concerns arise, contact Aladdin Scientific customer support with the lot number and CoA reference for technical assistance or return/replacement options.

Ordering and Availability

1-Bromo-4-(trimethylsilyl)but-3-yn-2-one is available from Aladdin Scientific under SKU B589116. Researchers and procurement managers can place orders directly through the Aladdin Scientific online store or by contacting regional sales representatives. The following information is useful for procurement:

• SKU: B589116
• Pack sizes: Contact Aladdin Scientific for available pack sizes and bulk pricing.
• Lead time: Standard in-stock items typically ship within 1–3 business days; confirm current inventory status at time of order.
• Documentation: SDS, CoA, and structural confirmation data are available upon request or through the product page on the Aladdin Scientific website.
• Export/Import: As a brominated organic compound, import licensing requirements may apply in certain jurisdictions. Consult your institutional procurement office and local regulations before ordering internationally.

For technical questions regarding specific applications, custom quantities, or reference standards, contact Aladdin Scientific's technical support team.