Site-selective amination of pyrimidines: regioselective C-2 functionalization
A palladium/NHC-catalyzed method that selectively aminates the 2-position of 2,4-dihalopyrimidines while leaving the 4-position intact for further modification, achieving greater than 99:1 regioselectivity and yields up to 91% under mild conditions.
Researchers at Montana State University have developed a highly efficient and selective method for synthesizing 2-(arylamino)-4-halopyrimidines from 2,4-dihalopyrimidines using palladium catalysis supported by N-heterocyclic carbene (NHC) ligands.
Background
2-(Arylamino)pyrimidines are essential motifs in pharmaceutical drugs such as protein kinase inhibitors. However, if a 4-substituent is also needed on the pyrimidine core, conventional synthetic routes are limited by the requirement to install the 4-substituent prior to the 2-arylamino group due to the greater reactivity of the 4-position in cross-coupling and nucleophilic aromatic substitution reactions. This invention addresses these challenges by enabling site-selective amination of 2,4-dihalopyrimidines at the C2 position under mild conditions, streamlining synthesis and reducing waste.
Technology Overview
The process employs palladium (II) complexes supported by bulky NHC ligands, optionally paired with neutral nitrogen donors, to achieve precise control over selectivity in amination cross-couplings of 2,4-dihalopyrimidines. In combination with mild inorganic bases and aromatic hydrocarbon solvents, the catalyst system promotes selective activation of the C2 halogen while preserving the C4 halogen for subsequent functionalization. Operating at approximately 50 °C under air or inert atmosphere, and with a low catalyst loading (1-2 mol %), the method consistently delivers >99:1 regioselectivity and yields up to 91%. It accommodates a broad range of arylamines and extends to 2,4-dihaloquinazolines and some substituted 2,4-dihalopyrimidines.
Benefits
- High selectivity minimizes costly purification steps
- Broad substrate scope for diverse applications
- Mild conditions simplify operations and reduce energy use
- Integration-ready for pharmaceutical and fine chemical workflows
Applications
- Drug discovery and medicinal chemistry
- Agrochemical synthesis
- Scalable manufacturing of pyrimidine-based APIs
Opportunity
Available for license: synthetic method, catalyst designs, and supporting data. Collaborative opportunities include optimization for specific substrates, scale-up, and integration into automated synthesis platforms
IP Status
Provisional patent application filed. Available for licensing and/or collaboration.
About Montana State University
Montana State University's substantial research enterprise growth has been accompanied by focused investments in innovation and research translation, creating new opportunities for companies to engage with MSU research and expertise. A particular strength is MSU’s network of specialized centers, institutes, and industry-accessible core facilities, which bring together multidisciplinary expertise, advanced research infrastructure, testing capabilities, and established pathways for working with industry partners. MSU is one of a select group of universities participating in the NSF's Accelerating Research Translation (ART) program, which is building the capacity and infrastructure needed to translate more research discoveries into solutions with real-world impact. The growing MSU Innovation Campus and expanding incubator infrastructure provide additional opportunities for university-industry interaction, startup development, and technology-focused companies. These efforts are complemented by MSU’s Technology Transfer Office, which works with researchers and companies to protect and license MSU inventions and facilitate industry-sponsored research collaborations.
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