In the intricate world of pharmaceutical manufacturing, the understanding of chemical intermediates is as crucial as the final API itself. This article focuses on 2-Butynoic Acid (CAS 590-93-2), a compound whose specific chemical properties make it an invaluable component in advanced organic synthesis, particularly for producing life-saving medications like Acalabrutinib. For R&D scientists and product formulators, grasping the nuances of this molecule is key to successful procurement and application.

Key Chemical and Physical Properties of 2-Butynoic Acid

2-Butynoic acid is characterized by its distinct chemical structure and physical attributes. As a carboxylic acid derivative containing an alkyne functional group, it offers unique reactivity for organic chemists. Here’s a breakdown of its essential properties:

  • Chemical Name: 2-Butynoic acid
  • CAS Number: 590-93-2
  • Molecular Formula: C4H4O2
  • Molecular Weight: 84.07 g/mol
  • Appearance: Typically observed as a light yellow crystalline powder. This physical form is convenient for handling and storage in laboratory and industrial settings.
  • Melting Point: 78-80°C. This moderate melting point indicates a stable solid at room temperature, facilitating its use in various reaction conditions.
  • Boiling Point: 200-203°C. A relatively high boiling point suggests thermal stability during certain processing steps.
  • Flash Point: 105°C. This parameter is important for safety considerations during handling and storage, indicating a moderate flammability risk.
  • Purity: High purity, often specified as ≥98.0% by HPLC, is critical for its pharmaceutical applications.

Applications in Pharmaceutical Synthesis: The Acalabrutinib Connection

The primary driver for the industrial demand of 2-Butynoic acid is its role as a key intermediate in the synthesis of Acalabrutinib. Acalabrutinib is a second-generation Bruton’s tyrosine kinase (BTK) inhibitor used in the treatment of certain B-cell malignancies, such as mantle cell lymphoma and chronic lymphocytic leukemia. The specific chemical reactivity of 2-butynoic acid allows for its effective incorporation into the complex molecular structure of Acalabrutinib, forming a critical amide bond through coupling reactions. Pharmaceutical companies looking to manufacture Acalabrutinib must secure a reliable source of high-purity 2-butynoic acid to ensure the quality and consistency of their API.

Beyond Pharmaceuticals: Other Synthetic Uses

While its prominence in Acalabrutinib synthesis is notable, 2-Butynoic acid is also a valuable synthon in broader organic chemistry. Its alkyne functionality and carboxylic acid group enable it to participate in a range of reactions, including:

  • Cycloacylation of phenols to form flavones and chromones.
  • Cyclization reactions to yield gamma-butyrolactones.
  • Synthesis of Z-trisubstituted olefins via Michael alkylation.
  • Preparation of chirally pure 1,2,3,4-tetrahydroisoquinoline analogs, which are often explored for their anti-cancer properties.

These applications highlight the versatility of 2-butynoic acid, making it a sought-after intermediate for both established chemical manufacturers and emerging R&D projects.

Conclusion: A Critical Intermediate for Innovation

2-Butynoic acid exemplifies the importance of specialized chemical intermediates in driving pharmaceutical innovation and production. Its precise chemical properties, coupled with the need for high purity, make it a critical component for manufacturers of Acalabrutinib. Understanding these properties empowers scientists and procurement professionals to make informed decisions when sourcing this essential building block. By choosing reliable suppliers who offer detailed product specifications and consistent quality, companies can ensure the efficient and successful development and manufacturing of vital pharmaceuticals.