The selective chlorination reaction of the aromatic ring among the aromatic compounds is very important in the economy and environmental protection aspects. A novel chlorination reaction system HCl-H₂O ₂-CH₃COOH was applied to react with o-xylene. Compared to the traditional Lewis acid catalysts which comprised sulfur and zeolite catalytic chlorination system, it took on much superiority such as high-selectivity, high-yield, simple operation, savings and environmental protection etc. The reaction conditions were controlled, the molar ratios of hydrogen peroxide, hydrochloric acid to o-xylene were 5.0,4.0 respectively, the reaction was processing under 70 ℃ until the feeding was finished and then the reaction was 2 h under 90 ℃. The conversion ratio of the raw material is over 99%, the yield is 96.9% and the selectivity is over 99% under this condition.

text-justify: inter-ideograph, text-align: justify, page-break-before: auto, line-height: normal, text-indent: 0pt, margin: 0pt, layout-grid-mode: both, direction: ltr, text-autospace: ideograph-numeric, word-break: normal, mso-pagination: none, mso-outline-level: body-text, mso-hyphenate: auto, mso-layout-grid-align: auto, punctuation-trim: none, punctuation-wrap: hanging, mso-line-break-override: none, mso-vertical-align-alt: auto" class="MsoNormal">font-variant: normal, font-family: Calibri, color: windowtext, font-size: 10.5pt, vertical-align: baseline, mso-ascii-font-family: Calibri, mso-fareast-font-family: 宋体">Lewis acid, Selectivity, p-Chlorination