Solid-Acid Catalyzed Continuous-Flow Aminolysis of Epoxides

Area of Science:

• Catalysis
• Organic Synthesis
• Chemical Engineering

Background:

• Aminolysis of epoxides is a key reaction for synthesizing valuable chemical intermediates.
• Developing efficient and sustainable catalytic systems for this transformation remains an active area of research.
• Continuous-flow processing offers advantages in terms of safety, scalability, and efficiency for chemical reactions.

Purpose of the Study:

• To develop a robust solid-acid catalyst for the aminolysis of epoxides under continuous-flow conditions.
• To investigate the catalyst's performance, substrate compatibility, and durability.
• To demonstrate the application of this method in a sequential-flow synthesis of a pharmaceutical intermediate.

Main Methods:

• A titania-zirconia supported molybdenum oxide catalyst was synthesized and characterized.
• The aminolysis of various epoxides with amines was performed in a continuous-flow reactor system.
• The catalyst's performance was optimized by adjusting the titania-zirconia ratio.
• A sequential-flow process combining hydrogenation and aminolysis was developed for a rivaroxaban intermediate synthesis.

Main Results:

• The developed catalyst exhibited excellent activity and selectivity for the synthesis of beta-amino alcohols.
• High yields and excellent catalyst durability were achieved across a range of epoxide substrates.
• The titania-zirconia ratio was identified as a critical factor for optimizing catalytic performance.
• A streamlined, sequential-flow synthesis of a rivaroxaban intermediate was successfully accomplished without intermediate isolation.

Conclusions:

• Solid-acid catalyzed aminolysis of epoxides in continuous flow is a highly efficient synthetic strategy.
• The titania-zirconia supported molybdenum oxide catalyst offers a sustainable and effective solution for beta-amino alcohol synthesis.
• This methodology provides a practical route for the industrial production of pharmaceutical intermediates, exemplified by the rivaroxaban intermediate synthesis.