20407-84-5Relevant articles and documents
Beckmann-rearrangement of cyclododecanone oxime to ω-laurolactam in the gas phase
Eickelberg,Hoelderich
, p. 42 - 55 (2009)
The classical route for the industrial production of ω-laurolactam is the homogeneously catalyzed Beckmann-rearrangement of cyclododecanone oxime in the liquid state using fuming sulfuric acid catalyst. Contrary to that, a completely different way is shown in the present work. In addition to the use of a solid acid catalyst, the vapor phase was chosen. From a process technical point of view it is a superior route compared with the classical one. Following intensive investigations of the vapor phase behavior of substrate, product and the main by-products, a catalyst screening of the most promising materials was performed. In addition, a modification of the most active catalysts was carried out to get more information about reaction sites and to optimize the catalyst activity. Using an acid treated [Al,B]-BEA zeolite at a temperature of approx. 320 °C and reduced pressures, complete conversion combined with excellent selectivity of 98% were obtained. The accumulation of reactants in the fixed bed was less than 5 wt%. Furthermore, investigations of deactivation and regeneration behavior of the catalyst were done. It could be demonstrated that the catalytic material could be regenerated under oxidative atmosphere as well as under non-oxidative conditions through thermal desorption of the deactivating compounds without any measurable loss of catalytic performance.
One-Pot Preparation of (E)-α,β-Unsaturated Aldehydes by a Julia-Kocienski Reaction of 2,2-Dimethoxyethyl PT Sulfone Followed by Acid Hydrolysis
Ando, Kaori,Watanabe, Haruka,Zhu, Xiaoxian
, p. 6969 - 6973 (2021/05/06)
(E)-α,β-Unsaturated aldehydes were synthesized by the Julia-Kocienski reaction of 2,2-dimethoxyethyl 1-phenyl-1H-tetrazol-5-yl (PT) sulfone 3 with various aldehydes, followed by acid hydrolysis. The reaction could be carried out in one pot, and various (E)-α,β-unsaturated aldehydes were obtained in a short time and with high yields.
A Simple, Mild and General Oxidation of Alcohols to Aldehydes or Ketones by SO2F2/K2CO3 Using DMSO as Solvent and Oxidant
Zha, Gao-Feng,Fang, Wan-Yin,Leng, Jing,Qin, Hua-Li
supporting information, p. 2262 - 2267 (2019/04/17)
A practical, general and mild oxidation of primary and secondary alcohols to carbonyl compounds proceeds in yields of up to 99% using SO2F2 as electrophile in DMSO as both the oxidant and the solvent at ambient temperature. No moisture- and oxygen-free conditions are required. Stoichiometric amount of inexpensive K2CO3, which generates easy to separate by-products, is used as the base. Thus, 5-gram scale runs proceeded in nearly quantitative yields by a simple filtration as the work-up. The use of a polar solvent such as DMSO, which usually promotes competing Pummerer rearrangement, is also noteworthy. This protocol is compatible with a variety of common N-, O-, and S-functional groups on (hetero)arene, alkene and alkyne substrates (68 examples). The protocol was applied (99% yield) to a formal synthesis of the important cholesterol-lowering drug Rosuvastatin. (Figure presented.).
