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Synfacts 2025; 21(07): 720
DOI: 10.1055/a-2601-4242
Polymer-Supported Synthesis

Knoevenagel and Claisen–Schmidt Condensations in Water Using NHSO3H-Functionalized Natural Asphalt

Contributor(s):
Yasuhiro Uozumi 
,
Aya Tazawa
Abdolahi S, Soleiman-Beigi M *. Ilam University, Iran
Exploring the Catalytic Activity of −NHSO3H Functionalized Natural Asphalt: A Sustainable and Efficient Catalyst for Condensation Reactions in Water.

RSC Adv. 2025;
15: 9280-9294
DOI: 10.1039/d5ra00870k
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Keywords

natural asphalt - sulfamic acid - Knoevenagel condensation - Claisen–Schmidt condensation

Significance

A sulfamic acid functionalized natural asphalt (NA-NH-SO3H), prepared according to equation 1, catalyzed the Knoevenagel condensation of benzaldehydes with malononitrile in H2O at room temperature to afford the corresponding Knoevenagel products (eq 2). NA-NH-SO3H also promoted the Claisen–Schmidt condensation of benzaldehydes with ketones (i. e., acetophenones, acetone, and cyclohexanone) to afford the corresponding chalcones and dibenzylidene ketones (e. 3).


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Comment

In the Knoevenagel condensation of benzaldehyde with malononitrile, the catalyst was recovered and reused five times without significant loss of its catalytic activity. FT-IR, SEM, and TG analyses of the recovered catalyst after the sixth run showed no obvious change in its morphology.


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Publication History

Article published online:
23 June 2025

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