摘要 |
Substituted carboxylic acids of the type prepared by the alkylation of maleic anhydride with an olefin polymer (e.g., polybutene) are prepared by a two-step method which is more economical and efficient than previously known methods. In the first step, the alkylating hydrocarbon is reacted with an unsaturated dicarboxylic acid or derivative thereof in an amount of the latter equal to about 30-90% by weight of the amount required to afford the desired product, optionally in the presence of a small amount of chlorine. In the second step, additional acid or derivative thereof is added and the reaction is continued in the presence of added chlorine. |