反应详情

85.0 gm of 2-pyrrolidone (1.0 mol) and 164 gm of H3PO3 (2.0 mols) were melted at 80°C. While stirring this melt, 176 ml of PCl3 (2.0 mols) were added thereto. The mixture was stirred for three additional hours and was left standing at 70°C overnight. Then, three liters of H2O were used for the hydrolysis. The solution was boiled with activated carbon; and after filtration, the reaction product was precipitated with acetone. The white substance was dissolved in water, and passed over a cation exchanger. The solution was concentrated; and the substance was separated upon the addition of ethanol. The yield of crystalline azacyclopentane-2,2-diphosphonic acid was 95 gm, or about 41% of the theory. The molecular weight of the compound was determined by titration to be 230 (calculated: 231.09).

1. additionwere added
2. waitwas left
3. filtrationand after filtration
4. customthe reaction product was precipitated with acetone
5. dissolutionThe white substance was dissolved in water
6. concentrationThe solution was concentrated
7. customand the substance was separated upon the addition of ethanol