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Tandem Aldol-Michael reactions in aqueous diethylamine medium: a greener and efficient approach to dimedone-barbituric acid derivatives.

Barakat A, Al-Majid AM, Al-Ghamdi AM, Mabkhot YN, Rafiq Hussain Siddiqui M, Ghabbour HA, Fun HK - Chem Cent J (2014)

Bottom Line: From this view point, it is desirable to use water instead of organic solvents as a reaction medium, since water is safe, abundant and an environmentally benign solvent.The structure of 4a was further confirmed by single crystal X-ray diffraction.An environmentally benign Aldol-Michael protocol for the synthesis of dimedone-barbituric derivatives using aqueous diethylamine medium is achieved.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Chemistry, College of Science, King Saud University, P,O, Box 2455, Riyadh 11451, Saudi Arabia. ambarakat@ksu.edu.sa.

ABSTRACT

Background: Green chemistry is a rapidly developing new field that provides us with a proactive avenue for the sustainable development of future science and technologies. Green chemistry uses highly efficient and environmentally benign synthetic protocols to deliver lifesaving medicines, accelerating lead optimization processes in drug discovery, with reduced unnecessary environmental impact. From this view point, it is desirable to use water instead of organic solvents as a reaction medium, since water is safe, abundant and an environmentally benign solvent.

Results: A convenient one-pot method for the efficient synthesis of the novel Zwitterion derivatives 4a-pvia a three-component condensation reaction of barbituric acid derivatives 1a,b, dimedone 2, and various aldehydes 3 in the presence of aqueous diethylamine media is described. This new approach is environmentally benign, with clean synthetic procedure, short reaction times and easy work-up procedure which proceeded smoothly to provide excellent yield (88-98%). The synthesized products were characterized by elemental analysis, IR, MS, NMR and CHN analysis. The structure of 4a was further confirmed by single crystal X-ray diffraction. The compound crystallizes in the orthorhombic space group Pbca with α = 14.6669 (5) Å, b = 18.3084 (6) Å, c = 19.0294 (6) Å, α = 90°, β = 90°, = 90°, V = 5109.9 (3) Å3, and Z = 8. The molecules are packed in crystal structure by weak intermolecular C-H⋅ ⋅ ⋅O hydrogen bonding interactions.

Conclusions: An environmentally benign Aldol-Michael protocol for the synthesis of dimedone-barbituric derivatives using aqueous diethylamine medium is achieved.

No MeSH data available.


Related in: MedlinePlus

Synthesis of 4a.
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C1: Synthesis of 4a.

Mentions: In a typical experimental procedure, a mixture of barbituric acid 1a,b, dimedone 2 and aromatic aldehyde 3 in water was stirred in the presence of a stoichiometric amount of diethylamine (1.0 equiv.) to afford the ‘Zwitterion adduct salts’ of dimedone-barbituric acid derivative 4a in high yields (Scheme 1).


Tandem Aldol-Michael reactions in aqueous diethylamine medium: a greener and efficient approach to dimedone-barbituric acid derivatives.

Barakat A, Al-Majid AM, Al-Ghamdi AM, Mabkhot YN, Rafiq Hussain Siddiqui M, Ghabbour HA, Fun HK - Chem Cent J (2014)

Synthesis of 4a.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC3924718&req=5

C1: Synthesis of 4a.
Mentions: In a typical experimental procedure, a mixture of barbituric acid 1a,b, dimedone 2 and aromatic aldehyde 3 in water was stirred in the presence of a stoichiometric amount of diethylamine (1.0 equiv.) to afford the ‘Zwitterion adduct salts’ of dimedone-barbituric acid derivative 4a in high yields (Scheme 1).

Bottom Line: From this view point, it is desirable to use water instead of organic solvents as a reaction medium, since water is safe, abundant and an environmentally benign solvent.The structure of 4a was further confirmed by single crystal X-ray diffraction.An environmentally benign Aldol-Michael protocol for the synthesis of dimedone-barbituric derivatives using aqueous diethylamine medium is achieved.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Chemistry, College of Science, King Saud University, P,O, Box 2455, Riyadh 11451, Saudi Arabia. ambarakat@ksu.edu.sa.

ABSTRACT

Background: Green chemistry is a rapidly developing new field that provides us with a proactive avenue for the sustainable development of future science and technologies. Green chemistry uses highly efficient and environmentally benign synthetic protocols to deliver lifesaving medicines, accelerating lead optimization processes in drug discovery, with reduced unnecessary environmental impact. From this view point, it is desirable to use water instead of organic solvents as a reaction medium, since water is safe, abundant and an environmentally benign solvent.

Results: A convenient one-pot method for the efficient synthesis of the novel Zwitterion derivatives 4a-pvia a three-component condensation reaction of barbituric acid derivatives 1a,b, dimedone 2, and various aldehydes 3 in the presence of aqueous diethylamine media is described. This new approach is environmentally benign, with clean synthetic procedure, short reaction times and easy work-up procedure which proceeded smoothly to provide excellent yield (88-98%). The synthesized products were characterized by elemental analysis, IR, MS, NMR and CHN analysis. The structure of 4a was further confirmed by single crystal X-ray diffraction. The compound crystallizes in the orthorhombic space group Pbca with α = 14.6669 (5) Å, b = 18.3084 (6) Å, c = 19.0294 (6) Å, α = 90°, β = 90°, = 90°, V = 5109.9 (3) Å3, and Z = 8. The molecules are packed in crystal structure by weak intermolecular C-H⋅ ⋅ ⋅O hydrogen bonding interactions.

Conclusions: An environmentally benign Aldol-Michael protocol for the synthesis of dimedone-barbituric derivatives using aqueous diethylamine medium is achieved.

No MeSH data available.


Related in: MedlinePlus