| 摘要 |
A 4,41-di(halomethyl)diphenyl oxide is made by halomethylation of diphenyl oxide by heating with formaldehyde and hydrogen chloride or hydrogen bromide in an acidic reaction medium, wherein the reaction is carried out in the presence of an acidic solvent which contains phosphoric acid and/or sulphuric acid and acetic acid. Preferably the phosphoric or sulphuric acid is in the proportion of 15 to 30% weight of the reaction mixture and acetic acid is in the proportion of 10 to 40% weight. The hydrogen halide may be used as a concentrated aqueous hydrochloric acid or hydrobromic acid. Preferably 2 to 4 moles of formaldehyde or paraformaldehyde and 2 to 4 moles of hydrogen chloride or bromide are used for each mole of diphenyl oxide. A reaction temperature of from 70 DEG to 100 DEG C. for from 3/4 to 3 hours may be used. The product is separated by cooling the reaction medium to 20-30 DEG C. to crystallize the product. Detailed examples of the production of 4,41-dichloromethyldiphenyl oxide and 4,41-dibromomethyldiphenyl oxide are given. |
