The Effect of Cetyltrimethylammonium Bromide on the 2-Iodosyl-5-octyloxy-benzoate-Catalyzed Hydrolysis of Active Esters and Related Compounds

1990 ◽  
Vol 43 (5) ◽  
pp. 937 ◽  
Author(s):  
DR Leslie ◽  
S Pantelidis
Keyword(s):  
Phase Separation ◽  
Cetyltrimethylammonium Bromide ◽  
Active Esters ◽  
Diphenyl Phosphate ◽  
Hydrolysis Of ◽  
Related Compounds ◽  
Separation Model

Enhancements provided by micellized cetyltrimethylammonium bromide ( ctab ), to the rates of reaction between 2-iodosyl-5-octyloxybenzoic acid and 4-nitrophenyl diphenyl phosphate (3), 4-nitrophenyl acetate (4), 1-methylethyl methylphosphonofluoridate (5), 1,2,2-trimethylpropyl methylphosphonofluoridate (6) and ethyl N,N- dimethylphosphoramidocyanidate (7) are determined over a range of ctab concentrations. The maximum enhancements observed for substrates (5)-(7) are greater than predicted by the phase-separation model.1 The suitability of themodel to describe these reactions is considered.

scholarly journals MICELLAR CATALYZED REACTION IN AQUEOUS GLYCEROL SOLUTIONS AND THE INTERNAL PRESSURE OF THE MEDIUM

2008 ◽  
Vol 16 (16) ◽  
pp. 41-57
Author(s):  
Lavinel G. IONESCU ◽  
Vera Lucia Trindade ◽  
Elizabeth Fatima de Souza
Keyword(s):  
Aqueous Solution ◽  
Internal Pressure ◽  
Sodium Hydroxide ◽  
Alkaline Hydrolysis ◽  
Cetyltrimethylammonium Bromide ◽  
Reaction Medium ◽  
Phosphate Ester ◽  
Cohesive Forces ◽  
Diphenyl Phosphate ◽  
Hydrolysis Of

The experimental results obtained/or the hydrolysis of p-nitrophenyl diphenyl phosphate (NPDPP) in the presence of sodium hydroxide (NaOH), micelles of cetyltrimethylammonium bromide (CTAB), and an aqueous solution of glycerol were analyzed taking into consideration the internal pressure and the cohesive forces of the reaction medium. The effect of glycerol on mice/le formation and also its influence on the internal pressure of the reaction medium are large enough to affect the micellar catalyzed alkaline hydrolysis of the phosphate ester.

scholarly journals Viscoelastic phase separation model for ternary polymer solutions

2021 ◽  
Vol 154 (10) ◽  
pp. 104903
Author(s):  
Kenji Yoshimoto ◽  
Takashi Taniguchi
Keyword(s):  
Phase Separation ◽  
Polymer Solutions ◽  
Ternary Polymer ◽  
Separation Model

Synthesis and Tautomerism of Curcumin Derivatives and Related Compounds

2015 ◽  
Vol 68 (2) ◽  
pp. 224 ◽  
Author(s):  
Hiroyasu Taguchi ◽  
Daijiro Yanagisawa ◽  
Shigehiro Morikawa ◽  
Koichi Hirao ◽  
Nobuaki Shirai ◽  
...  
Keyword(s):  
Parent Compound ◽  
Amyloid Plaques ◽  
Enol Form ◽  
19F Nmr ◽  
Enolic Form ◽  
Curcumin Derivatives ◽  
Alkyl Groups ◽  
Alzheimer Brain ◽  
Hydrolysis Of ◽  
Related Compounds

1,7-Bis(4′-hydroxy-3′-trifluoromethoxyphenyl)-1,6-heptadiene-3,5-dione (2a), related to curcumin, and thirteen 4-substituted derivatives were prepared and their keto/enol ratio in DMSO[D6] was determined by 19F NMR because the enolic form of these related curcumins had been shown to bind to amyloid plaques in the Alzheimer brain. The parent compound and the 4-ethoxycarbonyl derivative were almost 100 % in the enolic form that contains a conjugated hepta-1,4,6-trien-3-on-5-ol backbone. Enolisation decreased to varying amounts in the derivatives that had 4-substituted alkyl groups. Attempts to prepare the 4-hydroxypropyl derivative by hydrolysis of O-methoxymethyl 2m or O-tetrahydropyranyloxy 2n protected derivatives led to cyclised products. A related pyrimidine compound 6b that mimicked a fixed enol form was also prepared.

Micellar catalysis of organic reactions. VIII. Kinetic studies of the hydrolysis of 2-acetyloxybenzoic acid (aspirin) in the presence of micelles

1982 ◽  
Vol 35 (7) ◽  
pp. 1357 ◽  
Author(s):  
TJ Broxton
Keyword(s):  
Aqueous Solution ◽  
Cetyltrimethylammonium Bromide ◽  
Cetylpyridinium Chloride ◽  
Kinetic Studies ◽  
Base Catalysis ◽  
Plateau Region ◽  
General Base ◽  
Mechanism Of Hydrolysis ◽  
Ph Range ◽  
Hydrolysis Of

The hydrolysis of 2-acetyloxybenzoic acid in the pH range 6-12 has been studied in the presence of micelles of cetyltrimethylammonium bromide (ctab) and cetylpyridinium chloride (cpc). In the plateau region (pH 6-8) the hydrolysis is inhibited by the presence of micelles, while in the region where the normal BAC2 hydrolysis (pH > 9) occurs the reaction is catalysed by micelles of ctab and cpc. The mechanism of hydrolysis in the plateau region is shown to involve general base catalysis by the adjacent ionized carboxy group both in the presence and absence of micelles. This reaction is inhibited in the presence of micelles because the substrate molecules are solubilized into the micelle and water is less available in this environment than in normal aqueous solution.

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