Substituted anilides from chitin-based 3-acetamido-furfural.

Area of Science:

• Organic Chemistry
• Sustainable Chemistry
• Biomass Conversion

Background:

• Sustainable synthesis of aromatic compounds from biomass is crucial for a circular economy.
• Chitin-derived furans offer a renewable feedstock for chemical synthesis.
• Nitrogen-containing aromatics are valuable building blocks in pharmaceuticals and materials.

Purpose of the Study:

• To develop an efficient method for synthesizing diverse di- and tri-substituted anilides from chitin-based furans.
• To explore the utility of hydrazone-mediated Diels-Alder/aromatization cascade reactions.
• To demonstrate the conversion of chitin-based precursors into valuable aromatic compounds.

Main Methods:

• Utilized a hydrazone-mediated Diels-Alder/aromatization cascade reaction starting from chitin-based 3-acetamido-furfural (3A5F).
• Investigated the effect of acetic anhydride on expanding dienophile scope and improving yields.
• Compared dimethyl hydrazone with its pyrrolidine analogue to optimize reaction conditions, including time and yield.
• Demonstrated the versatility of the hydrazone auxiliary by converting it to aldehyde or nitrile groups.
• Applied the developed procedure to 3-acetamido-5-acetylfuran (3A5AF) for phthalimide synthesis.

Main Results:

• Achieved good to high yields (62-90%) for a range of di- and tri-substituted anilides.
• Acetic anhydride addition enhanced dienophile scope and overall yields.
• The pyrrolidine hydrazone analogue significantly reduced reaction times and increased yields compared to dimethyl hydrazone.
• Successfully synthesized a phthalimide derivative from 3A5AF, showcasing the method's broader applicability.
• The hydrazone auxiliary provided a facile route to diverse functionalized anilides.

Conclusions:

• The developed hydrazone-mediated Diels-Alder/aromatization cascade is a powerful and efficient strategy for synthesizing functionalized anilides from biomass-derived furans.
• This method offers a sustainable route to valuable nitrogen-containing aromatic compounds, contributing to a greener chemical industry.
• The versatility of the hydrazone auxiliary and the applicability to different chitin-based precursors highlight the robustness of this synthetic approach.