33798-77-5Relevant academic research and scientific papers
Investigation on recovery of p-mephso3k based on solid-liquid equilibrium of the p-mephso3k-k2co3-h2o system
Shuanghong, Hao,Jie, Xu,Mengqi, Chen,Yan, Wei
, p. 1249 - 1254 (2021)
In this article, we propose a method of recovering p-MePhSO3K from the industrial by-product of quizalofop-p-ethyl. The phase diagram of the solid-liquid equilibrium system of p-MePhSO3K2CO3-H2O at the temperatures of 15, 25, 35, 45, and 55°C was determined and plotted. Based on the phase diagram of 25°C, the separation and recovery process of p-MePhSO3K from the p-MePhSO3K2CO3-H2O system was designed by analyzing the crystallization fields. First, p-MePhSO3K and K2CO3 were crystallized from wastewater in turn through evaporation separation. Then, the crystallized p-MePhSO3K was purified further by washing with ethanol. Finally, the pure p-MePhSO3K was transformed into the intermediate p-toluenesulfonyl chloride and then the intermediate L-p-toluenesulfonate ethyl lactate for quizalofop-p-ethyl production.
Detailed Characterization of p-Toluenesulfonic Acid Monohydrate as a Convenient, Recoverable, Safe, and Selective Catalyst for Alkylation of the Aromatic Nucleus
Mahindaratne, Mathew P. D.,Wimalasena, Kandatege
, p. 2858 - 2866 (2007/10/03)
Alkylation of the aromatic nucleus, an important reaction in industry and synthetic organic chemistry, has traditionally been carried out by the well-known Friedel-Crafts reaction employing Lewis acid catalysts such as AlCl3 and BF3 or by using highly reactive organometallic reagents. Although protic acids such as anhydrous HF and concentrated H2SO4 have also been used in the alkylation of the aromatic nucleus, the notoriously corrosive, highly toxic, and hazardous nature of these agents has precluded their common use under ordinary laboratory conditions. Various organic sulfonic acids have, on occasion, been used as catalysts in Friedel-Crafts alkylations, but to our knowledge the chemistry and the scope of these reactions for common laboratory use have never been exploited in detail. In the present study we have characterized commercially available p-toluenesulfonic acid monohydrate (TsOH) as an efficient catalyst for the intermolecular coupling of the aromatic nucleus with activated alkyl halides, alkenes, or tosylates under mild conditions in an open atmosphere. In comparison to conventional Friedel-Crafts catalysts such as AlCl3, BF3, HF, and concentrated H2SO4, the extent of the formation of undesired products from side reactions such as transalkylation, polymerization, etc. was minimal with the TsOH-catalyzed reaction. The ability to recover and reuse the catalyst from the reaction mixtures, minimal generation of environmentally unfriendly waste, high specificity of the reaction, and the low cost of the catalyst are important advantages of the TsOH catalyst over the other conventional Friedel-Crafts catalysts.
SYNTHESIS OF THE ENANTIOMERS OF CIS-2-METHYL-5-HEXANOLIDE, THE MAJOR COMPONENT OF THE SEX PHEROMONE OF THE CARPENTER BEE
Mori, Kenji,Senda, Shuji
, p. 541 - 546 (2007/10/02)
(2R,5S)-2-Methyl-5-hexanolide and its antipode were synthesized in highly optically pure state (98-99percent e.e.) starting from ethyl (S)-lactate and the enantiomers of methyl β-hydroxyisobutyrate.The specific rotations of our samples were D +/- 91.0 -93.5 deg (CHCl3), while the reported values of the samples prepared by resolution or asymmetric synthesis were +/- 64.5-65.6 deg.
