scholarly journals Investigations of the reactivity of pyridine carboxylic acids with diazodiphenylmethane in protic and aprotic solvents: Part II: Pyridine mono-carboxylic acid N-oxides

2006 ◽  
Vol 71 (2) ◽  
pp. 89-101 ◽  
Author(s):  
Sasa Drmanic ◽  
Bratislav Jovanovic ◽  
Aleksandar Marinkovic ◽  
Milica Misic-Vukovic
Keyword(s):  
Regression Analysis ◽  
Reaction Mechanism ◽  
Carboxylic Acid ◽  
Carboxylic Acids ◽  
Rate Constants ◽  
Picolinic Acid ◽  
Correlation Coefficients ◽  
Aprotic Solvents ◽  
Pyridine Carboxylic ◽  
Similar Range

The rate constants for the reaction of three isomeric pyridine mono-carbocylic acid N-oxides with diazodiphenylmethane were determined at 30 ?C in thirty two protic and aprotic solvents by the well known UV spectrophotometric method. The rate constants are generally higher than for pyridine mono-carboxylic acids in a similar range of solvents, except for picolinic acid N-oxide, and also higher in protic than in aprotic solvents. The determined rate constants were correlated with solvent parameters using the Kamlet-Taft solvatochromic equation bymeans of multiple regression analysis. The sign of the equation coefficients were in agreement with the postulated reaction mechanism. The mode of the influences of the solvent is discussed on the basis of the correlation coefficients, taking into account the specific structures of the pyridine mono-carboxylic acid N-oxides.

scholarly journals Investigations of the reactivity of pyridine carboxylic acids with diazodiphenylmethane in protic and aprotic solvents, Part I: Pyridine mono-carboxylic acids

2005 ◽  
Vol 70 (4) ◽  
pp. 557-567 ◽  
Author(s):  
Aleksandar Marinkovic ◽  
Sasa Drmanic ◽  
Bratislav Jovanovic ◽  
Milica Misic-Vukovic
Keyword(s):  
Carboxylic Acids ◽  
Rate Constants ◽  
Kinetic Data ◽  
Reaction Rate ◽  
Linear Regression Analysis ◽  
Multiple Linear Regression Analysis ◽  
Aprotic Solvents ◽  
Solvent Parameters ◽  
Protic Solvents ◽  
Pyridine Carboxylic

Rate constants for the reaction of diazodiphenylmethane with isomeric pyridine carboxylic acids were determined in chosen protic and aprotic solvents at 30 ?C, using the well known UV spectrophotometric method. The values of the rate constants of the investigated acids in protic solvents were higher than those in aprotic solvents. The second order rate constants were correlated with solvent parameters using the Kamlet-Taft solvatochromic equation in the form: logk = logk0 + s?*+ a? + b?. The correlation of the obtained kinetic data were performed by means of multiple linear regression analysis taking appropriate solvent parameters. The signs of the equation coefficients were in agreement with the postulated reaction mechanism. The mode of the influence of the solvent on the reaction rate in all the investigated acids are discussed on the basis of the correlation results.

Influence of Diflufenzopyr Addition to Picolinic Acid Herbicides for Russian Knapweed (Acroptilon repens) Control

2009 ◽  
Vol 23 (3) ◽  
pp. 450-454 ◽  
Author(s):  
Stephen F. Enloe ◽  
Andrew R. Kniss
Keyword(s):  
Carboxylic Acid ◽  
Carboxylic Acids ◽  
Picolinic Acid ◽  
Weed Species ◽  
Pyridine Carboxylic Acid ◽  
Russian Knapweed ◽  
Pyridine Carboxylic ◽  
Acroptilon Repens ◽  
Acid Herbicides

Diflufenzopyr is a synergist that has improved the efficacy of certain auxin-type herbicides such as dicamba on many broadleaf weed species. However, little is known regarding the activity of diflufenzopyr with other auxin-type herbicides. Russian knapweed is an invasive creeping perennial that is susceptible to certain pyridine carboxylic acids, which are auxin-type herbicides. The objective of this research was to determine if the addition of diflufenzopyr to three pyridine carboxylic acid herbicides enhances long-term control of Russian knapweed in Wyoming. All treatments were applied in the fall. Treatments included aminopyralid (0, 0.05, 0.09, and 0.12 kg ae/ha), clopyralid (0, 0.16, 0.21, 0.31, and 0.42 kg ae/ha) and picloram (0, 0.14, 0.28, 0.42, and 0.56 kg ae/ha), applied with and without diflufenzopyr (0.06 and 0.11 kg ae/ha). Twelve mo after treatment (MAT), diflufenzopyr had no significant impact on Russian knapweed control with either aminopyralid or picloram, and had significant but inconsistent impacts on knapweed control with clopyralid. At 24 MAT, diflufenzopyr did not enhance Russian knapweed control with either aminopyralid or clopyralid and was slightly antagonistic with picloram. These results indicate that the addition of diflufenzopyr does not improve Russian knapweed control with fall applications of either aminopyralid, clopyralid, or picloram.

scholarly journals New Stable Manganese(III) Chelates of Some Pyridine Carboxylic Acids

1981 ◽  
Vol 36 (10) ◽  
pp. 1270-1272 ◽  
Author(s):  
Saktiprosad Ghosh ◽  
Pranab K. Ray ◽  
Tapas K. Bandyopadhyay ◽  
Amal K. Deb
Keyword(s):  
Carboxylic Acid ◽  
Dicarboxylic Acid ◽  
Carboxylic Acids ◽  
Tricarboxylic Acid ◽  
Pyridine Carboxylic ◽  
Physicochemical Methods

Abstract The syntheses of three new and unusually stable Mn(III) complexes of pyridine-2-carboxylic acid, pyridine-2,6-dicarboxylic acid and pyridine-2,4,6-tricarboxylic acid and their characterisation by various standard physicochemical methods is reported

THE ORTON REARRANGEMENT IN APROTIC SOLVENTS: PART II. THE ACID-CATALYZED BROMINATION OF ANISOLE BY A SERIES OF 4-SUBSTITUTED N-BROMOACYLANILIDES

1965 ◽  
Vol 43 (4) ◽  
pp. 732-740 ◽  
Author(s):  
John M. W. Scott ◽  
June G. Martin
Keyword(s):  
Carboxylic Acid ◽  
Carboxylic Acids ◽  
Aprotic Solvents ◽  
Acid Catalyzed

Anisole has been brominated using a sequence of brominating reagents generated by the reaction of a series of 4-substituted N-bromoacylanilides 4-RC6H4NBrAc (R = Ph, H, Cl, and NO2) with a series of carboxylic acids R′COOH (R′ = CF3, CCl3, CH2Cl, and CH3). The isomer distributions of the bromoanisoles produced have been measured for each N-bromoacylanilide–carboxylic acid pair and their variation with both the structure of the N-bromoacylanilide and the carboxylic acid provides a useful basis for a discussion of the mechanism of the bromine migration.

A kinetic investigation of the effects of molecular complexing on the acidities of some π donor carboxylic acids

1977 ◽  
Vol 55 (6) ◽  
pp. 1028-1038 ◽  
Author(s):  
Allan K. Colter ◽  
R. James Kersting
Keyword(s):  
Carboxylic Acid ◽  
Acrylic Acid ◽  
Carboxylic Acids ◽  
Rate Constants ◽  
Association Constants ◽  
Second Order ◽  
Kinetic Investigation ◽  
Rate Data ◽  
Dihydroxybenzoic Acid ◽  
Order Rate

Rates of reaction of the five π donor acids indole-3-acrylic acid (IAA), indole-5-carboxylic acid (ICA), 3,4,5-trimethoxybenzoic acid (TMBA), 2,4-dihydroxybenzoic acid (DHBA), and 3,4,5-trihydroxybenzoic acid (THBA) with 4-chlorodiphenyldiazomethane (4-ClDDM) in ethanol at 30 °C were measured in the presence of the π acceptors 1,3,5-trinitrobenzene (TNB), benzotrifuroxan (BTF), and 1,2,4,5-tetracyanobenzene (TCNB) and in the absence of acceptor. For 12 of the 13combinations studied, added acceptor produced rate enhancements. The rate data were combined with independently-determined 1:1 acceptor – donor acid association constants to obtain second-order rate constants for reaction of the 1:1 acceptor – donor acid complexes. From the increase in the rate constant resulting from complexation, estimates of the increase in Ka(H2O, 25 °C) produced by complexation were obtained for 13 acceptor – donor acid combinations. Second-order rate constants for reaction of 4-ClDDM with 10 other carboxylic acids and p-toluenesulfonic acid in ethanol at 30°C were also measured and the pattern of reactivity shown to parallel very closely that of diphenyldiazomethane.

THE ORTON REARRANGEMENT IN APROTIC SOLVENTS: III. THE ACID-CATALYZED CHLORINATION OF ANISOLE BY A SERIES OF 4-SUBSTITUTED N-CHLOROACYLANILIDES

1966 ◽  
Vol 44 (23) ◽  
pp. 2901-2907 ◽  
Author(s):  
John M. W. Scott ◽  
June G. Martin
Keyword(s):  
Carboxylic Acid ◽  
Carboxylic Acids ◽  
Transfer Reaction ◽  
Probable Mechanism ◽  
Aprotic Solvents ◽  
Acid Catalyzed ◽  
Reported Data

Anisole has been chlorinated with a sequence of chlorinating agents generated by the reaction of a series of 4-substituted N-chloroacylanilides (4-X-C6H4NClAc (X = Me, H, and CN)) with a series of carboxylic acids (R—COOH (R = CF3, CCl3, CH2Cl, and CH3)). The isomer ratios of the 2- and 4-chloroanisoles produced in these reactions have been measured for each N-chloroacylanilide – carboxylic acid pair, and are found to be dependent on the strength of the catalyzing acid but independent of the structure of the N-chloroacylanilide within the precision of the reported data. These observations are consistent with both the termolecular scheme proposed in part II of this series and the Soper mechanism. However, evidence derived from these and other observations suggests that the termolecular scheme is still the most probable mechanism for the chlorine transfer reaction.

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