| Popis: |
In previous syntheses of aspartic acid the following reactions have been used: The decomposition of acid ammonium malate by heat,1 the racemization of active aspartic acid2 and active asparagine,3 the reaction of maleic or fumaric acid with ammonia,4 the reduction of oxalacetic ester oxime,5 the reaction of silver fumarate or potassium acid fumarate with hydroxylamine hydrochloride,6 the reduction of nitrosuccinic ester,7 the catalytic reduction and ammonation of oxalacetic acid,8 and the hydrolysis of the addition compound formed from sodium malonic ester and chloroacetic ester.9The present synthesis is believed to be more satisfactory than those previously reported for aspartic acid.Phthalimido malonic ester, prepared from potassium phthalimide and bromodiethylmalonate, was converted to sodium phthalimido malonic ester by allowing it to react with molten metallic sodium suspended in toluene. A stable addition product was then formed as a dark colored oil by the reaction of chloroacetic ester with sodium... |
