1-Bromo-2-butyne, also known as 2-butynyl bromide, is a chemical compound that holds significant importance in the field of organic synthesis due to its unique combination of functional groups and predictable reactivity. Understanding its fundamental chemical properties is key to harnessing its potential in various synthetic applications, from the creation of complex pharmaceutical intermediates to the synthesis of intricate natural products.

Physically, 1-Bromo-2-butyne typically presents as a colorless to light yellow liquid. Its density is approximately 1.519 g/mL at 25 °C, and it possesses a boiling point of 40-41 °C at 20 mmHg. The flash point is reported as 97 °F, indicating its flammability, and it is miscible with solvents like acetonitrile. These physical characteristics are crucial for chemists when planning reactions, considering storage, and ensuring safe handling.

Chemically, the molecule's structure, C4H5Br, features a terminal bromine atom attached to a secondary carbon, adjacent to a triple bond. This propargylic bromide structure makes it highly reactive in nucleophilic substitution reactions. The bromine atom can be readily displaced by various nucleophiles, facilitating the formation of new carbon-heteroatom or carbon-carbon bonds. This reactivity is central to its use as a versatile building block in organic synthesis.

The alkyne functionality also opens up a wide array of synthetic possibilities. It can participate in addition reactions, cycloadditions, and coupling reactions, such as the Sonogashira coupling, allowing for the introduction of diverse substituents and the construction of more complex molecular frameworks. For example, its application in the synthesis of annulated ring compounds highlights its utility in creating cyclic structures found in many biologically active molecules.

The compound's role as an intermediate in the synthesis of pharmaceuticals, such as Linagliptin, and natural products, like Pseudopterane (+/-)-Kallolide B, underscores its chemical significance. These applications demonstrate its ability to undergo selective transformations that are critical for building precise molecular architectures. NINGBO INNO PHARMCHEM CO.,LTD. offers 1-Bromo-2-butyne with high purity, ensuring that chemists can rely on its consistent chemical behavior for their synthetic endeavors.

In essence, the well-defined chemical properties of 1-Bromo-2-butyne make it an indispensable reagent for chemists seeking to synthesize complex molecules efficiently and predictably. Its dual reactivity—as a propargylic halide and an alkyne—positions it as a powerful tool in the ongoing advancement of organic chemistry and its related fields.