Fungicidal aluminium ethyl phosphite prepn. - by reaction of alumina with ternary mixts. of di:ethyl-phosphite, mono:ethyl-phosphite and phosphorous acid

摘要

Prepn. of aluminium ethylphosphite comprises reaction of an excess of a ternary equilibrium mixt. of 23-93% of diethylphosphite, 59-7% of monoethylphosphite and 18-0.1% of phosphorous acid on opt hydrated alumina at 20-100 degrees C under reduced pressure, the water produced in the reaction being eliminated simultaneously. Process gives high yields and good reproducibility of product, used as a plant fungicide. Process is suitable for industrial scale. In a typical reaction, a mean yield of 96% was obtd. by reaction of a mixt. of 43% diethylphosphite, 49% of monoethylphosphite and 8% of phosphorous acid with alumina type H10 at 25-60 degrees C to give 95.2% aluminium ethylphosphite.