Phase transfer catalysed permanganate oxidation of hydroxymethyl to carboxylic acid

10.1039/sp458 ◽  
2010 ◽  
Author(s):  
Christopher Cooksey
Keyword(s):  
Carboxylic Acid ◽  
Phase Transfer ◽  
Permanganate Oxidation

scholarly journals Synthesis of Galectin Inhibitors by Regioselective 3′-O-Sulfation of Vanillin Lactosides Obtained under Phase Transfer Catalysis

Molecules ◽  
2020 ◽  
Vol 26 (1) ◽  
pp. 115
Author(s):  
Karima Belkhadem ◽  
Yihong Cao ◽  
René Roy
Keyword(s):  
Carboxylic Acid ◽  
Sulfur Trioxide ◽  
Phase Transfer Catalysis ◽  
Phase Transfer ◽  
Aldehyde Group ◽  
Para Position ◽  
Knoevenagel Reaction ◽  
Aromatic Residue ◽  
Unsaturated Carboxylic Acid ◽  
Catalyzed Reactions

Vanillin-based lactoside derivatives were synthetized using phase-transfer catalyzed reactions from per-O-acetylated lactosyl bromide. The aldehyde group of the vanillin moiety was then modified to generate a series of related analogs having variable functionalities in the para- position of the aromatic residue. The corresponding unprotected lactosides, obtained by Zemplén transesterification, were regioselectively 3′-O-sulfated using tin chemistry activation followed by treatment with sulfur trioxide-trimethylamine complex (Men3N-SO3). Additional derivatives were also prepared from the vanillin’s aldehyde using a Knoevenagel reaction to provide extended α, β-unsaturated carboxylic acid which was next reduced to the saturated counterpart.

scholarly journals Synthesis by Reversed Phase Transfer Catalysis and Characterization of Naphthol AS-D Pigment

2013 ◽  
Vol 2013 ◽  
pp. 1-4
Author(s):  
Eleonora Cornelia Crasmareanu ◽  
Vasile Simulescu ◽  
Gheorghe Ilia
Keyword(s):  
Carboxylic Acid ◽  
Organic Phase ◽  
Reaction Rate ◽  
Phase Transfer Catalysis ◽  
Phase Transfer ◽  
Coupling Reaction ◽  
Reversed Phase ◽  
Azo Coupling ◽  
Unconventional Method

Reversed phase transfer catalysis (RPTC) was applied to synthesize the Naphthol AS-D pigment. This method consists in the transfer of the aryldiazonium cation 4-nitrobenzenediazonium from aqueous medium into the organic phase (nitrobenzene) in the form of a lipophilic ions pair by the catalyst used (perfluorooctyl potassium sulfonates). In the organic phase the azo-coupling reaction between 4-nitrobenzenediazonium chloride and 3-hydroxy-2-carboxylic acid 2-methyl-anilide (Naphthol AS-D) takes place as coupling component. Using this unconventional method of synthesis, an increase of the reaction rate, combined with a higher purity of the product, was obtained.

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