| 摘要 |
1,228,720. (cis-1,2-Epoxypropyl) phosphonic acid and salts thereof. MERCK & CO. Inc. 12 May, 1969 [15 May, 1968], No. 23972/69. Heading C2C. A mixture of (+) and (-) enantiomers of {cis-1,2-epoxypropyl) phosphonic acid or a salt of such mixture, e.g. an alkali metal, ammonium, or amine salt, e.g. the monobenzylamine salt, is reacted in solution with a metal salt of an optically active acid or with a metal salt of a mixture of optically active acid enantiomers to produce a metal salt of (cis-1,2-epoxypropyl) phosphonic acid containing a greater proportion of one of the enantiomers and recovering this from the reaction mixture. The metal salt of the optically active acid, whose cation is preferentially transferred to one or other enantiomer of (cts-l,2-epoxypropyl) phosphonic acid, may be an alkali metal salt, an alkaline earth metal salt, a Mg salt, a transition heavy metal metal salt, or a Pb, Al or Sn salt and a wide variety of optically active acids are mentioned. Specified salts used in the examples are calcium (+) gluconate monohydrate, calcium (-) lactate pentahydrate, racemic calcium lactate pentahydrate, cupric ( + ) gluconate monohydrate, magnesium (+ ) lactate trihydrate, calcium ( + ) lactate pentahydrate and an epoxypolyamine ion exchange resin which contains (-) phenylalanine residues on the Cu+ + cycle. Any salt of the epoxy acid isomers which will permit the preferential transfer of the salt-forming cation of the salt of the optically active acid and which will keep the optically active acid and one of the enantiomers soluble in the reaction mixture can be used. Suitable solvents for carrying out the process include water, C 1 -C 5 alkanols, C 1 -C 5 aqueous alkanols, and aprotio solvents, e.g. dimethyl sulphoxide, N,N-dimethylformamide and tetrahydrothiophene dioxide, or mixture of such solvents. Racemio (cis 1,2-epoxypropyl) phosphonic acid is prepared by selective catalytic hydrogenation of 1-propynyl phosphonic acid to form cispropenyl phosphonic acid followed by epoxidation of the latter with H 2 0 2 , a detailed example of each step being given. An example is also given for the conversion of the ammonium salt of the racemic epoxy acid to the monobenzylamine salt by treatment with benzylamine in methanol. (+) Cis (1,2-epoxypropyl) phosphonic acid can be converted to cis propenyl phosphonic acid by heating with potassium thiocyanate in aqueous methanol and can be converted to the (-) enantiomer by splitting the epoxide ring of a salt of the (+) compound by reaction with CF 3 COOH to form [1 -hydroxy-2-(trifluoroacetoxy) propyl]-phosphonate salt, reacting the latter with methane sulphonyl chloride in CH 2 Cl 2 and pyridine to produce [1-(methanesulphonyloxy) - 2- (trifluoroacetoxy) propyl] phosphonate salt and treating the latter in methanol solution with NaOH to produce sodium (-) (cis- 1,2-epoxypropyl) phosphonate. |
