Phosphoric Acid → HCID 18788097, compound

Participants

Reaction Steps

11.68 g (0.05 mol) of 3-(1,5-dimethyl-3-aza-bicyclo[3,1,1]hept-3-yl)-propionic acid hydrochloride, 6.6 ml of 84% phosphoric acid and 23 ml of chlorobenzene are heated to 105° with stirring. 13.5 ml of phosphorus trichloride are slowly added dropwise and the reaction mixture is subsequently maintained at 105° for a further 3 hours. The chlorobenzene is then distilled off under reduced pressure, leaving a viscous mass. 50 ml of water are added to the latter and the mixture is boiled under reflux for 1 hour with stirring. The mixture is then completely concentrated by evaporation under reduced pressure. Upon stirring the residue with acetone and decanting, a colourless oil is obtained which is then dissolved in 50 ml of hot water. Upon adding 140 ml of hot methanol and cooling, colourless crystals of 3-(1,5-dimethyl-3-aza-bicyclo[3,1,1]hept-3-yl)-1-hydroxy-propane-1,1-diphosphonic acid are obtained; m.p. 245°-247° (decomposition); formula ##STR14## The 3-(1,5-dimethyl-3-aza-bicyclo[3,1,1]hept-3-yl)-propionic acid hydrochloride used as starting material can be prepared in the following manner:

Provenance & Evidence