Solid-phase synthesis of diverse spiroisoxazolinodiketopiperazines

Area of Science:

• Organic Chemistry
• Medicinal Chemistry
• Synthetic Chemistry

Background:

• Diketopiperazines are privileged scaffolds in medicinal chemistry.
• Spirocyclic compounds offer unique three-dimensional structures for drug discovery.
• Efficient synthesis of diverse libraries is crucial for identifying novel drug candidates.

Purpose of the Study:

• To develop a novel, efficient, and parallel solid-supported synthesis protocol.
• To prepare diverse libraries of spiroisoxazolino-diketopiperazines.
• To adapt reaction steps for automated or semi-automated synthesis equipment.

Main Methods:

• Solid-supported synthesis utilizing a four-step sequence.
• Key reactions include amino acid coupling, tosylation with β-elimination, 1,3-dipolar cycloaddition, and resin cleavage.
• Parallel synthesis approach for library generation.

Main Results:

• A 100-member demonstration library of spiroisoxazolino-diketopiperazines was successfully synthesized.
• The protocol yielded products with good purity.
• Acceptable overall yields were achieved for the synthesized library.

Conclusions:

• The developed protocol provides a convenient and efficient route to diverse spiroisoxazolino-diketopiperazines.
• Solid-supported synthesis enables rapid library generation suitable for automated platforms.
• This method facilitates the exploration of novel chemical space for drug discovery.