16456-56-7 3-01-00-01509 (Beilstein Handbook Reference) BRN 0969857 Butyl hydrogen phosphonate Butyl phosphite Butyl phosphonate ((Bu-O)-(O-H)-(H-P-O)) (7CI) Butylfosfit [Czech] EINECS 240-508-1 Monobutyl phosphite Phosphonic acid, monobutyl ester Phosphorous acid, butyl ester