- ALKYLATION OF PENTAERYTHRITOL BY PHASE-TRANSFER CATALYSIS 2. Crucial Effect of the Aqueous Sodium Hydroxyde Solution
-
The mechanistic aspects of the alkylation of pentaerythritol (2-2'-bis(hydroxymethyl)-1,3-propanediol) (PE) by phase-transfer catalysis have been investigated.The dramatic effect of an excess and renewal of sodium hydroxide solutions on the one hand, and the solubility of the PT catalyst in the organic phase on the other, argue that the selectivity of this reaction appears to be controlled almost completely by the possible protonation of the sodium form of the alkoxide anion of PE (4).This protonation depends on the assumption that water molecules are present in the PT medium, and it based upon the observation that this PT medium is actually a three liquid-layer system.As the unusual layer (catalyst layer) may be readily hydrated, the concentrated sodium hydroxide solution can be no longer considered as an unquestionable desiccant.
- Nouguier, Robert,Mchich, Mohamed
-
p. 2477 - 2482
(2007/10/02)
-
- Alkylation of Pentaerythritol and Trimethylolpropane, Two Very Hydrophilic Polyols, by Phase-Transfer Catalysis.
-
Two very hydrophilic polyols, pentaerythritol and trimethylolpropane , can be etherified in good yields by phase-transfer catalysis with allyl chloride or heptyl bromide as alkylating agents.Ion pairs solubilities, lipophilicities of catalysts, and nature of the reaction products which are key factors in achievement of this PTC reaction are discussed.
- Nouguier, R. M.,Mchich, M.
-
p. 3296 - 3298
(2007/10/02)
-
- Synthese des ethers du pentaerythritol par catalyse en transfert de phase. Optimisation de la reaction d'etherification pour leur synthese industrielle
-
The very hydrophilic pentaerythritol can be etherified with 1-bromo-heptane by phase transfer catalysis (PTC).The resulting mixture of ethers is an original synthetic additive.The PTC reaction was then optimized to increase the total yield, and to lower the cost of the final product.To our knowledge, it is the first industrial optimization of a PTC reaction.
- Nouguier, Robert,Mchich, Mohamed,Maldonado, Paul,Grangette, Henri
-
p. 602 - 607
(2007/10/02)
-