3586-14-9Relevant articles and documents
Synthesis of m-phenoxybenzaldehyde starting from chlorobenzene and m-cresol: Some aspects of process development
Chandnani, Kavita H.,Chandalia, Sampatraj B.
, p. 416 - 424 (1999)
m-Phenoxybenzaldehyde (MPB) is an important intermediate for synthetic pyrethroids. In the present paper, an economic process scheme was developed to synthesize MPB starting from cheaper reactants. The process scheme was started with the synthesis of m-phenoxytoluene (MPT). Oxidation of MPT by air gave MPB, but the selectivity was found to be high at low conversions of about 10%, and if the conversion level was increased, then large amounts of the undesired m-phenoxybenzoic acid (MPBA) was formed. To obtain the desired aldehyde, Rosenmund reduction of MPBA was carried out to give high yields of the MPB. The effects of different parameters such as catalyst, substrate concentration, temperature, etc., were studied for all three of the reactions, viz., Ullmann ether synthesis, oxidation, and Rosenmund reduction. MPT was prepared from chlorobenzene, a relatively cheaper starting material, in the presence of polyethylene glycol) as cosolvent and cuprous chloride as the catalyst. A selectivity of 97% was obtained with 86% conversion to the product. Oxidation of MPT was carried out by air in the presence of cobalt acetate as catalyst and sodium bromide as catalyst promoter. The selectivity with respect to the aldehyde and the ester was 37.4 and 30.6%, respectively, at a restricted overall conversion of 24%. The process parameters were controlled to achieve high selectivity towards the aldehyde. The acid, formed as the side product, was reduced to the aldehyde by Rosenmund reduction via the acyl chloride. At a conversion level of 85%, a selectivity of 87% to MPB was obtained using Pd/C.
L-Proline N-oxide dihydrazides as an efficient ligand for cross-coupling reactions of aryl iodides and bromides with amines and phenols
Ding, Zhiqiang,Nie, Nan,Chen, Tian,Meng, Lingxin,Wang, Gongshu,Chen, Zhangpei,Hu, Jianshe
supporting information, (2020/12/21)
A novel catalytic system based on L-proline N-oxide/CuI was developed and applied to the cross-coupling reactions of various N- and O- nucleophilic reagents with aryl iodides and bromides. This strategy featured in the employment of an-proline derived dihydrazides N-oxide compound as the superior supporting ligand. By using this protocol, a variety of products, including N-arylimidazoles, N-arylpyrazoles, N-arylpyrroles, N-arylamines, and aryl ethers, were synthesized with up to 99% yield.
Preparation method of m-phenoxy benzaldehyde
-
Paragraph 0075-0076, (2021/04/28)
The invention provides a preparation method of m-phenoxy benzaldehyde, and belongs to the technical field of organic synthesis. The preparation method provided by the invention comprises the following steps: condensing m-cresol serving as a raw material with halogenated benzene to obtain m-phenoxytoluene, reacting the m-phenoxytoluene with chlorine to chloridize methyl to obtain a m-phenoxytoluene chloro product, oxidizing the m-phenoxytoluene chloro product through Komblum to obtain an oxide of the m-phenoxytoluene chloro product, and directly hydrolyzing the m-phenoxytoluene chloro product without separation to obtain the product m-phenoxy benzaldehyde. The preparation method provided by the invention has the advantages that the raw materials are cheap and easily available, the yield is high, the product quality meets the market demand, the problems of high raw material price, many side reactions, many impurities, low yield, large wastewater amount and serious environmental pollution in the traditional process are solved, and the production cost of m-phenoxybenzaldehyde is greatly reduced. Data of the embodiment shows that the total yield of m-phenoxybenzaldehyde obtained by the preparation method provided by the invention is 83.5%, and the gas phase content is 99.3%.
Trimethoxyphenyl (TMP) as a Useful Auxiliary for in situ Formation and Reaction of Aryl(TMP)iodonium Salts: Synthesis of Diaryl Ethers
Gallagher, Rory T.,Basu, Souradeep,Stuart, David R.
, p. 320 - 325 (2019/12/11)
Herein, we describe a synthetic approach for arylation that exploits the in situ formation and reaction of an unsymmetrical diaryliodonium salt. In this way, aryl iodides are used as reagents in a metal-free reaction with phenols, and a trimethoxyphenyl (TMP) group is used as a “dummy” group to facilitate transfer of a wide range of aryl moieties. The scope of aryl electrophiles and phenol nucleophiles is broad (>30 examples) and the yields are high (52–95%, 80% avg.). One-pot coupling reactions avoid the synthesis of diaryliodonium salts and provide opportunities for sequential reactions and novel chemoselectivity. (Figure presented.).
