| 摘要 |
<p>Prodn. of diphosphonic acids of formula (HO)2P(O).C(NH2)(R).P(O)(OH)2 (I) comprises reacting H3PO3 with an appropriately substd. nitrile RCN as described in the parent patent (R = H2nX. X = CN, COOR', Ph, CmH2m-1, OR2, SR2, SO2R3, N(R2)2, O=P(R22)(R1)(sic) or C10H7. R1 = H or CnH2n+1. R2 = H, R1 or CnH2nCN. n = 1-11, m is not defined). Pref. reaction is at 110-180 degrees C. The yield of (I) can be increased by including a Lewis acid e.g. AlCl3. Pref. reaction is in an aprotic solvent of b.pt. >140 degrees C, e.g. sulpholone, dimethylsulphone or diglycol diethyl ether. Salts of (I) are useful as chelating agents and stabilisers e.g. in water treatment, textile processing and paper mfr.</p> |
