(1-Amino-3-(diethoxyphosphinyl)propylidene)bisphosphonic acid dihydrate 69549-53-7 Phosphonic acid, (1-amino-3-(diethoxyphosphinyl)propylidene)bis-, dihydrate alpha-Amino-gamma-diethoxyphosphonopropylidene-alpha,alpha-diphosphoic acid dihydrate