Aromatics chloromethylated study of the oxidation reaction and benzyl chloride
|School||Nanjing University of Technology and Engineering|
|Keywords||Aromatics Chloromethylated Oxidation Micellar catalysis Potassium nitrate Phase Transfer Catalysis Benzyl chloride Cation exchange resin|
The surface active agent and a phase transfer catalyst as two environmentally friendly catalyst, being awareness and acceptance of their aqueous solutions may be used directly as the reaction solvent, and volatile organic solvents as compared with the currently widely used irreplaceable advantages. The chloromethylation and benzyl aromatics chlorine oxidation reaction is for two types of organic synthesis is extremely important and very broad application response to this thesis, the surfactant and the phase transfer catalysts are used in catalytic aromatics chloromethylated and benzyl chloride The oxidation reaction of detailed studies were carried out from two aspects. (1) the chloromethylated aromatic hydrocarbon by the micellar catalysis: cumene (IPB), the reaction substrate, using micellar catalysis method, the effects of the type of surfactant, the surfactant concentration, reaction time, chloroformate group reagent and other factors influence on the reaction to optimize the process, the optimum conditions were found to improve the conversion rate and selectivity (including single chloromethylated selective and selective bit product), to achieve a series of aromatic compounds chloromethyl, and to study the mechanism of the micellar catalysis chlorine methylation reaction. The study showed that: micellar catalysis achieve aromatics (especially the more reactive arene) chloromethylated effective method, cationic surface active agents, especially those having a longer carbon chain, cationic surfactants such as cetyl trimethyl the catalytic effect of the ammonium bromide (CTAB) is preferably 14 times of CMC, n (cumene): n (poly-formaldehyde): n (NaCl) = 1:1.2:2, the reaction temperature is 80 ℃ and reaction time 4h conditions cumene conversion rate can reach 98.0%, the single chloromethylated selectivity 97.5%, the regioselectivity (para / ortho) ratio 10.1:1. (2) a phase transfer catalytic oxidation of benzyl chloride: under acidic conditions, the use of phase transfer catalysis, to the benzyl chloride as a reaction substrate, with potassium nitrate as the oxidizing reagent, optimize the process, the effects of the oxidation reaction of a variety of factors impact. The optimum conditions for improving the conversion rate of benzyl chloride and benzaldehyde selectivity: n (benzyl chloride): n (KNO 3 ): n (cation exchange resin 001 × 7) = 1: 1.1:1.5, PEG-600 as a phase transfer catalyst, water as solvent, N 2 protection back 6h. Under this condition, the conversion of benzyl chloride was 95.4%, the target benzaldehyde selectivity and yield were 99.0% and 94.5%. This method is applied to the oxidation of the compound of a series of benzyl chloride, the results show that all the benzyl chloride can be successfully converted to the corresponding aldehyde or ketone.