Two-step method for the alkenylation of maleic anhydride and related compounds

Claim 1

In a method for preparing a substituted carboxylic acid or derivative thereof which comprises reacting (A) at least one substantially aliphatic hydrocarbon having about 30-300 carbon atoms and containing on olefinic bond but being otherwise substantially saturated with (B) about 0.3-2.0 moles, per mole of reagent A, of at least one of maleic acid, fumaric acid, itaconic acid, and anhydrides and esters of any of these acids, at least a part of the reaction taking place in the presence of chlorine, the improvement which comprises: (I) Reacting reagent A with an amount of reagent B equal to about 30-90% of the amount required to afford the desired product, at a temperature within the range of about 100°-250° C. and in the presence of about 0-0.4 mole of chlorine per mole of reagent B; and subsequently (II) Introducing additional reagent B sufficient to afford the desired product and continuing the reaction at a temperature within the range of about 170°-225° C. and in the presence of about 0.9-4 moles of added chlorine per mole of said additional reagent B; the total amount of chlorine used in said method being substantially less than one mole per mole of reagent B.