| 摘要 |
1,204,967. Alkylene - diphosphonic acids. MONSANTO CO. 8 May, 1968 [8 May, 1967 (2)], No. 21828/68. Heading C2C. [Also in Divisions C3 and C5] Novel compounds of the general formula where R represents hydrogen or methyl, or alkali metal salts, alkaline earth metal salts or heavy metal salts thereof, or amine or ammonium salts thereof, or alkyl or substituted alkyl esters thereof, are prepared by thermally dehydrating a metal salt of 1-hydroxy, ethylidene (or propylidene)-1,1-diphosphonic acid to yield the desired metal salts. The free acids, the esters and other salts are prepared from the metal salts by conventional means. The preferred esters are C 1-6 alkyl, halo-alkyl and hydroxy-alkyl esters. |
