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Microwave-assisted synthesis of mono- and disubstituted 4-hydroxyacetophenone derivatives via Mannich reaction: synthesis, XRD and HS-analysis

Aljohani, Ghadah and Said, Musa A. and Lentz, Dieter and Basar, Norazah and Albar, Arwa and Alraqa, Shaya Y. and Al-Sheikh Ali, Adeeb (2019) Microwave-assisted synthesis of mono- and disubstituted 4-hydroxyacetophenone derivatives via Mannich reaction: synthesis, XRD and HS-analysis. Molecules, 24 (3). pp. 1-14. ISSN 1420-3049

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Official URL: http://dx.doi.org/10.3390/molecules24030590

Abstract

An efficient microwave-assisted one-step synthetic route toward Mannich bases is developed from 4-hydroxyacetophenone and different secondary amines in quantitative yields, via a regioselective substitution reaction. The reaction takes a short time and is non-catalyzed and reproducible on a gram scale. The environmentally benign methodology provides a novel alternative, to the conventional methodologies, for the synthesis of mono- and disubstituted Mannich bases of 4-hydroxyacetophenone. All compounds were well-characterized by FT-IR, 1H NMR, 13C NMR, and mass spectrometry. The structures of 1-{4-hydroxy-3-[(morpholin-4-yl)methyl]phenyl}ethan-1-one (2a) and 1-{4-hydroxy-3-[(pyrrolidin-1-yl)methyl]phenyl}ethan-1-one (3a) were determined by single crystal X-ray crystallography. Compound 2a and 3a crystallize in monoclinic, P21/n, and orthorhombic, Pbca, respectively. The most characteristic features of the molecular structure of 2a is that the morpholine fragment adopts a chair conformation with strong intramolecular hydrogen bonding. Compound 3a exhibits intermolecular hydrogen bonding, too. Furthermore, the computed Hirshfeld surface analysis confirms H-bonds and π–π stack interactions obtained by XRD packing analyses.

Item Type:Article
Uncontrolled Keywords:mannich bases, microwave irradiation, regioselectivity, X-ray
Subjects:Q Science > QD Chemistry
Divisions:Science
ID Code:89372
Deposited By: Yanti Mohd Shah
Deposited On:22 Feb 2021 14:07
Last Modified:22 Feb 2021 14:07

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