1H-Pyrazole-4-carboxylic acid(CAS: 37718-11-9)

1H-Pyrazole-4-carboxylic acid is a white to off-white crystalline solid with a molecular weight of approximately 131.12 g/mol. It has a pKa of 3.2 and a partition coefficient (log P) of -0.5, indicating a slightly acidic nature and moderate lipophilicity. The compound is slightly soluble in water and ethanol but soluble in organic solvents like dichloromethane and acetone. It demonstrates reactivity towards nucleophiles and can undergo condensation reactions and amide formations.

1H-Pyrazole-4-carboxylic acid can be synthesized via a multi-step route starting from 2-bromo-1H-pyrazole or other precursors. Common methods include the condensation of 2-bromo-1H-pyrazole with carboxylic acids or the reduction of 1H-pyrazole-4-carboxaldehyde. The synthesis often uses conditions such as sodium hydride or sodium borohydride as reducing agents, and the process yields can range from 50% to 75%, depending on the specific reaction conditions and purity of starting materials.

1H-Pyrazole-4-carboxylic acid finds applications in various industries, particularly in pharmaceuticals, where it serves as a precursor for the synthesis of drug candidates. It is also used in the production of polymers and sensors due to its functional groups, which facilitate chemical reactions and interactions. Additionally, it has potential in the semiconductor industry for use in the fabrication of electronic materials.

When handling 1H-Pyrazole-4-carboxylic acid, it is important to wear appropriate personal protective equipment (PPE), including gloves, goggles, and a lab coat. Ensure the work is conducted in a well-ventilated area or a fume hood to minimize inhalation risks. Spills should be cleaned up immediately with appropriate absorbent materials and the area should be thoroughly rinsed. Always consult the Safety Data Sheet (SDS) for detailed handling and disposal information, and follow all local safety regulations.