Dissociation of Amides in Strongly Basic Medium of Sodium Methoxide in Dimethyl Sulfoxide-Methanol Mixtures

1997 ◽  
Vol 62 (10) ◽  
pp. 1562-1576
Author(s):  
Petr Mitaš ◽  
Jaromír Kaválek ◽  
Oldřich Pytela
Keyword(s):  
Dimethyl Sulfoxide ◽  
Sodium Methoxide ◽  
Dissociation Constants ◽  
Basic Medium ◽  
Acidity Function

The dissociation constants of eleven amides have been measured in methanol and its mixtures with dimethyl sulfoxide (10 to 80% v/v) using sodium methoxide as the base. The experimental dissociation constants have been used to construct the H- acidity function as a function of methoxide concentration and composition of the DMSO-MeOH mixture as well as function of methoxide concentration in methanol. Moreover, with the help of construction of acidity function, the functions have been devised for constant sodium methoxide concentrations (0.025, 0.1, and 0.2 mol l-1) and changing composition of the DMSO-MeOH mixture.

Vicarious nucleophilic amination of nitroquinolines with 4-amino-1,2,4-triazole

2008 ◽  
Vol 86 (7) ◽  
pp. 682-685 ◽  
Author(s):  
Barbara Szpakiewicz ◽  
Maria Grzegożek
Keyword(s):  
Dimethyl Sulfoxide ◽  
Nucleophilic Substitution ◽  
Nitro Group ◽  
Para Position ◽  
Basic Medium ◽  
Ortho Position ◽  
Vicarious Nucleophilic Substitution

3-, 5-, 6-, 7- and 8-Nitroquinolines react with 4-amino-1,2,4-triazole in basic medium (potassium tert-butoxide-dimethyl sulfoxide) giving amino products of the vicarious nucleophilic substitution (VNS) of hydrogen, predominantly at ortho position to the nitro group, except 8-nitroquinoline, which reacts at para position. Additionally, furazano[3,4-f]- and furazano[3,4-h]quinoline were obtained in the case of 5- and 8- nitroquinoline, respectively. 2-Nitroquinoline was aminated to 2-quinolino(1,2,4-triazol-4-yl)amine in these conditions.Key words: nitroquinolines, vicarious nucleophilic substitution (VNS), 4-amino-1,2,4-triazole.

scholarly journals Cleavage of the methylenedioxy group with sodium methoxide in dimethyl sulfoxide.

1978 ◽  
Vol 26 (10) ◽  
pp. 3113-3116 ◽  
Author(s):  
SHIGERU KOBAYASHI ◽  
MASARU KIHARA ◽  
YOSHINOBU YAMAHARA
Keyword(s):  
Dimethyl Sulfoxide ◽  
Sodium Methoxide ◽  
Methylenedioxy Group

Synthesis and Gas Sensing Property of Poly(m-aminophenol)

2013 ◽  
Vol 710 ◽  
pp. 89-92
Author(s):  
Wei Ping Tang
Keyword(s):  
Fourier Transform ◽  
Aqueous Solutions ◽  
Dimethyl Sulfoxide ◽  
Laser Scanning ◽  
Gas Sensing ◽  
Ammonium Persulfate ◽  
Confocal Microscope ◽  
Basic Medium ◽  
Laser Scanning Confocal Microscope ◽  
Ethanol Sensing

Poly (m-aminophenol) (PmAP) was synthesized chemically from aqueous solutions of the monomer meta-aminophenol in the initially basic medium by using ammonium persulfate as an oxidant. The synthesized PmAP was characterized by Fourier transform infrared spectroscopic. The film of PmAP was formed by dissolving PmAP in the dimethyl sulfoxide followed by solvent removel. The morphology of the film was obeserved by laser scanning confocal microscope (LSCM) and the ethanol sensing property was studied by testing the resistance of the PmAP film when purged air and ethanol alternately.

Re-examination of the Kirkwood–Westheimer theory of electrostatic effects. III. Dissociation constants of cis-3- and trans-4-substituted cyclohexanecarboxylic acids in water–dimethyl sulfoxide mixtures

1978 ◽  
Vol 56 (8) ◽  
pp. 1130-1133 ◽  
Author(s):  
Jitka Kirchnerova ◽  
Patrick G. Farrell ◽  
John T. Edward ◽  
Jean-Claude Halle ◽  
Robert Schaal
Keyword(s):  
Dimethyl Sulfoxide ◽  
Dissociation Constant ◽  
Dissociation Constants ◽  
Solvent Composition ◽  
Potentiometric Method ◽  
Acid Dissociation ◽  
Electrostatic Effects ◽  
Acid Dissociation Constants ◽  
Cyclohexanecarboxylic Acid

Acid dissociation constants of two cis-3- and of four trans-4-substituted cyclohexanecarboxylic acids in water – dimethyl sulfoxide mixtures of varying composition were determined by a potentiometric method. Results have been analyzed according to the model of Kirkwood and Westheimer, and shown to differ from calculated values because of certain oversimplifications built into the model. Dissociation constant differences between cyclohexanecarboxylic acid and the compounds studied vary only slightly with changing solvent composition.

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