Methacrylic Acid → Iron(2+) methacrylate

For example, a method has been proposed, in which methacrylic acid, an alkaline metal and an iron salt such as iron nitrate are mixed in a solvent such as water, and iron methacrylate is produced by salt exchange (Patent Literature 1). Since this method has a difficulty in securely completing salt exchange, iron methacrylate is difficult to obtain in a high yield of 90% or higher. The method has further problems such as a reduction in purity due to contamination of iron methacrylate with impurities derived from nitric acid, and a rise in the cost because of necessity of filtration and drying processes. In the case where a hydroxyalkyl methacrylate is produced by using the prepared iron methacrylate as a catalyst, there are concern about problems, such as by-production of impurities, coloration and the like derived from nitric acid contained in the catalyst raw material.