| 摘要 |
1360998 Purification of α-6-deoxytetracyclines I VILLAX 28 June 1971 [3 July 1970 10 Sept 1970 9 June 1971] 30121/71 Heading C2A A process for the purification of α-6-deoxytetracyclines from a reaction mixture containing, besides α-6-deoxytetracyclines, reaction byproducts, degradation products and the # isomer as impurities, is characterized in that the crude reaction mixture is acidified with a concentrated aqueous solution of a strong organic or inorganic acid, then heated up to a temperature of 60-90‹ C. until the impurities are further degraded, the reaction mixture is cooled and the α-6-deoxytetracyclines are recovered by precipitation as a water-insoluble derivative and subsequent formation of the free base, the hydrochloride or the calcium salt. Suitable tetracyclines which may be purified by this method include α - 6 - deoxytetracycline, α - 6 - deoxy- 5 - hydroxytetiacycline, α - 6 - deoxy - 7- chlorotetracycline and α-6-deoxy-7-chloro-5- hydoxytetracycline. Suitable acids are methanesulphonic acid, sulphuric acid and hydrochloric acid in concentrations between 2 and 18 per cent. |
