Process for directed chlorination of alkylbenzenes
AssigneeHooker Chemicals & Plastics Corporation
InventorHenry C. Lin
Life of this patent
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Abstract
A process for the production of nuclear chlorinated alkylbenzenes comprises reacting, in the liquid phase, alkylbenzene with chlorine in the presence of a Lewis acid catalyst and a co-catalyst comprising a thianthrene compound or mixture of thianthrene compounds characterized by the formula: ##STR1## WHERE EACH N IS 0 TO 1, EACH X IS HYDROGEN OR AN ELECTRON-WITHDRAWING SUBSTITUENT OR AN ELECTRON-DONATING SUBSTITUENT WITH THE PROVISO THAT AT LEAST ONE X IS AN ELECTRON WITHDRAWING SUBSTITUENT AND AT LEAST ONE X IS ELECTRON-DONATING SUBSTITUENT. A preferred co-catalyst is dimethyldichlorothianthrene. The monochlorinated alkylbenzene products prepared in this manner are characterized by a desirably low ratio of ortho to para isomer.
Claims24
A process for the preparation of nuclear chlorinated alkylbenzenes which comprises reacting an alkylbenzene with chlorine in the presence of a Lewis acid catalyst and a co-catalyst comprising a thianthrene compound or mixture of thianthrene compounds characterized by the formula:
- ##STR5## where each n is 0 to 1 and each x is hydrogen or an electron-withdrawing substituent or an electron-donating substituent with the proviso that at least one x is an electron-withdrawing substituent and at least one x is an electron-donating substituent.
A process for the preparation of monochlorotoluene which comprises reacting toluene with chlorine at a temperature of about 0.degree. to about 110.degree. Celsius, in the presence of a catalyst system comprising a Lewis acid catalyst selected from the group consisting of chlorides oxychlorides oxides and elemental forms of antimony and iron;
- and a co-catalyst comprising a thianthrene compound or mixture of thianthrene compounds characterized by the formula ##STR6## wherein each x is hydrogen, lower alkyl, or an electron-withdrawing substituent selected from the group consisting of fluoro-, chloro, bromo-, and trifluoromethyl-, with the proviso that at least one x is lower alkyl, and at least one x is an electron withdrawing substituent.
Dependencies are inferred from the claim text.