Structural aspects of phenoxyalkanoic acids. The structures of phenoxyacetic acid, (+–)-2-phenoxypropionic acid, (+–)-2-(4-chlorophenoxy)propionic acid, 2-methyl-2-phenoxypropionic acid and 2-(4-chlorophenoxy)-2-methylpropionic acid

Kennard, C. H. L.; Smith, Graham; White, Allan H.

doi:10.1107/s0567740882004269

Cited by 35 publications

(11 citation statements)

References 7 publications

(10 reference statements)

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“…[119] However,t he protons of D 2 Oc ould be present at approximately d = 4.7 ppm, and the assignment of H-B was covered by the assignment of D 2 O, thus the classical 1D NMR spectroscopy approach was inappropriate for the presentation H-B. [119] However,t he protons of D 2 Oc ould be present at approximately d = 4.7 ppm, and the assignment of H-B was covered by the assignment of D 2 O, thus the classical 1D NMR spectroscopy approach was inappropriate for the presentation H-B.…”

Section: D 1 H-1 Hcosy Spectroscopymentioning

confidence: 99%

Synthesis and Characterization of Carboxyethylated Lignosulfonate

Bahrpaima

Fatehi

2018

ChemSusChem

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Lignosulfonate is a byproduct of the sulfite pulping process and has limited use in industry. The main objective of this study was to investigate the carboxyethylation of lignosulfonate to increase its charge density to broaden its applications. The carboxyethylation of lignosulfonate was optimized under the conditions of 30 wt % NaOH, 2.0 mol mol 2-chloropropinic acid/lignosulfonate, 90 °C, 0.5 h, and 0.03 mol 2-chloropropinic acid, which produced carboxyethylated lignosulfonate with a charge density and molecular weight of -3.51 meq g and 46 493 g mol , respectively. The mechanism of the carboxyethylation reaction using 2-chloropropinic acid by an S 1 pathway in an alkaline solution was discussed. Methylation was also used to mask the phenolic hydroxide groups of lignosulfonate to investigate if carboxyethylation occurred on aliphatic hydroxide groups of lignosulfonate. The produced carboxyethylated lignosulfonate was characterized by using FTIR spectroscopy, NMR spectroscopy, gel permeation chromatography, and elemental and functional group analyses. Basic H- H 2 D COSY NMR spectroscopy was used to record the coupled spins of the carboxyethyl group on carboxyethylated lignosulfonate. The information from 1 D H NMR and 2 D NMR COSY spectroscopy provided evidence for the existence of a 1-carboxyethyl group on the carboxyethylated lignosulfonate structure.

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Section: D 1 H-1 Hcosy Spectroscopymentioning

confidence: 99%

Synthesis and Characterization of Carboxyethylated Lignosulfonate

Bahrpaima

Fatehi

2018

ChemSusChem

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“…TPPO complexes are characteristically stabilized by strong hydrogen bonds between the phosphoryl oxygen and the proton donor of the adduct (in this case a carboxylic acid group). Since the structures of the parent compounds are known ([2,4-D] Smith et al, 1976;[4-ABA] Alleaume et al, 1966;Lai and Marsh, 1967;[TPPO] Spek, 1987;Ruban and Zabel, 1976;Bandoli et al, 1970), structural comparisons can be made, particularly relating to the 2,4-D molecules (Kennard et al, 1982). Since the structures of the parent compounds are known ([2,4-D] Smith et al, 1976;[4-ABA] Alleaume et al, 1966;Lai and Marsh, 1967;[TPPO] Spek, 1987;Ruban and Zabel, 1976;Bandoli et al, 1970), structural comparisons can be made, particularly relating to the 2,4-D molecules (Kennard et al, 1982).…”

Section: Introductionmentioning

confidence: 99%

The (1:1) adducts of (2,4-dichlorophenoxy)- acetic acid with 4-aminobenzoic acid and triphenylphosphine oxide

Lynch¹,

Smith²,

Byriel³

et al. 1992

Zeitschrift Für Kristallographie - Crystalline Materials

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The (1:1) molecular adducts between the herbicide (2,4dichlorophenoxy)acetic acid (2,4-D) and 4-aminobenzoic acid, [(2,4-D)(4-ABA)], (1) and triphenylphosphine oxide, [(2,4-D)(TPPO)], (2) have been determined by X-ray diffraction and refined to residuals R = 0.077 and 0.054 for 1588 and 5051 observed reflections respectively. With adduct (1), the planar molecules of 2,4-D and 4-ABA form into hydrogen bonded tetramer units via the carboxylic acid groups of 2,4-D and the amino groups of 4-ABA (Ο N, 2.74, 2.75 A). These units then hydrogen bond, giving molecular stacks (Ο N, 2.81 A). In contrast, the two independent molecules of 2,4-D in the asymmetric unit of (2) are antiplanar and are hydrogen bonded to the TPPO molecules [2.58, 2.61 A]. The two independent TPPO molecules are also conformational^ dissimilar.

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“…Permeation studies across an established skin mimic, namely silicone membrane were performed using Franztype diffusion cells that have a receptor phase of ~5 ml, and a diffusional area of 0.788cm 2 . Sheets of silicone membrane were cut to appropriate sizes in round-shape and soaked overnight in the receptor phase (mixture of PBS and methanol; 1:1 v/v).…”

Section: Permeation Across Skin Mimicmentioning

confidence: 99%

“…Transdermal delivery systems are considered to be a control release dosage forms and it should be scientifically supported for in vivo and in vitro claims of controlled release features and therefore have to be approved based on clinical safety and efficacy studies [6,7]. Chemical permeation enhancers facilitate the absorption of permeant through the skin by temporarily decreasing the impermeability of the skin [2]. Penetration of drugs into and through the skin involves passive diffusion which occurs very slowly and is the only means to transfer drugs across the skin [8].…”

Section: Introductionmentioning

confidence: 99%

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Optimization and Permeation Study of Novel Topically Applied Antilipemic Lotion Using Central Composite Design

Aslam¹,

Riaz²,

Shahzad³

et al. 2014

AJPS

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In this study, synergistic effect of penetration enhancers, namely propylene glycol (PG) and sodium lauryl Sulphate (SLS) on transdermal absorption of 2-Methyl-2-phenoxy-propionic acid (MPA) was evaluated with aid of response surface methodology (RSM) based formulations. The prepared formulations were characterised and subsequently subjected to diffusion cell experiments through a well-established skin mimic, namely silicone membrane. Data obtained were statistically analysed using analysis of variance (ANOVA) and regression analysis. Comparisons were made with the control and among different parameters of formulations. PG (X1) and SLS (X2) were selected as independent variables, whereas the cumulative amount of MPA were used to calculate dependent permeation kinetic parameters like lag time (t lag ) and enhancement ratios (ER). It was observed from the results that PG had a significant effect on MPA absorption from the lotion followed by SLS and their combination showed a significant enhancement (p< 0.05) in the flux from the formulated lotions compared to the control. The highest enhancement ratio (ER=8.6) was observed for L4. Contour plots were then drawn to depict the relationship between independent and response variables. Among the formulations, L4 showed highest flux value with less lag time (12.2 min), thereby, identified and selected as an optimized formulation. In conclusion, the combination of PG and SLS can be successfully utilized as permeation enhancers for transdermal drug delivery of MPA with minimal side effects.

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Structural aspects of phenoxyalkanoic acids. The structures of phenoxyacetic acid, (+–)-2-phenoxypropionic acid, (+–)-2-(4-chlorophenoxy)propionic acid, 2-methyl-2-phenoxypropionic acid and 2-(4-chlorophenoxy)-2-methylpropionic acid

Cited by 35 publications

References 7 publications

Synthesis and Characterization of Carboxyethylated Lignosulfonate

Synthesis and Characterization of Carboxyethylated Lignosulfonate

The (1:1) adducts of (2,4-dichlorophenoxy)- acetic acid with 4-aminobenzoic acid and triphenylphosphine oxide

Optimization and Permeation Study of Novel Topically Applied Antilipemic Lotion Using Central Composite Design

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