| 摘要 |
The invention comprises 2,5-diphenyl-piperazine, and the acid addition salts, including penicillin salts, thereof, and the preparation thereof by hydrogenating 2,5-diphenyl-pyrazine or a 2,5-diphenyl-dihydro-pyrazine in the presence of a hydrogenation catalyst and an inert solvent for said pyrazine. The hydrogen catalyst is preferably a palladium-carbon catalyst and the inert solvent is preferably formic acid. The acid addition salts may be derived from an organic or mineral acid, the hydrochloride and acetate salts being referred to specifically. The penicillin salts may be derived from penicillin F, G, K or X, the 2,5-diphenyl-piperazine combining with 2 mols. of the penicillin used. A suitable method for the preparation of the penicillin salts is by double decomposition using a water-soluble salt of 2,5-diphenyl-piperazine, e.g. the acetate salt, and a water-soluble salt of penicillin, e.g. the triethylamine salt, in an aqueous solution. The double decomposition process may be modified to use other solvents in which the salt of piperazine is soluble and an alkali or alkaline earth metal salt of penicillin or a salt of penicillin with any organic base. It is also possible to form a penicillin salt of 2,5-diphenyl-piperazine by reacting penicillin acid with 2,5-diphenyl-piperazine in an organic solvent for the reactants and isolating the required penicillin salt, e.g. by evaporation or the addition of another solvent. In the examples, 2,5-diphenyl-piperazine is prepared by hydrogenating 2,5-diphenyl - 3,6 - dihydro - pyrazine and 2,5 - diphenylpyrazine in the process of palladium/carbon catalyst, and is converted into the hydrochloride and bipenicillinate G salts.ALSO:Penicillin salts of 2, 5-diphenyl piperazine are employed in stock raising. An example is concerned with the preparation of colourless, prismatic needles of the bipenicillinate G of 2, 5-diphenyl piperazine of water solubility 0,35 parts per thousand.ALSO:A therapeutic composition comprises a salt of 2,5-diphenyl-piperazine with a penicillin and a carrier. The composition may be in the form of a suspension, e.g. in distilled water, in a saline solution, or in an aqueous propylene glycol solution, or the composition may be formed in an oil, e.g. in arachis oil, sesame oil, cottonseed oil or other suitable triglyceride. Other agents which may be present are stabilizing, thixotropic, and wetting agents, and viscosity modifiers. The composition may be in the form of compressed tablets or granules. The composition is suitable for application to plants and for addition to animal feedstuffs when a liquid carrier for the salt is used. Particular penicillins referred to from which the salts may be derived are penicillin F, G, K and X, and mixtures of such salts may also be used. |
