RHODIUM CONTAINING CATALYST AND USE THEREOF IN PREPARATION OF 6-DEOXY-5-OXYTETRACYCLINE

摘要

1477995 Rhodium-containing hydrogenation catalyst; preparing 6 - deoxy - 5 - oxytetracycline PFIZER Inc 27 Jan 1976 [28 Jan 1975] 03184/76 Headings C2P and C2C A rhodium-containing hydrogenation catalyst is obtained by reacting 1 mol of rhodium trichloride, e.g. in the form of its trihydrate, with 2 mols of sodium acetate in methanol at a temperature from 50‹ C. to the flux temperature of the reaction mixture, then reacting the resulting reaction mixture with 2 mols of triphenyl phosphine at from 50‹ C. to the reflux temperature of the reaction mixture and recovering (e.g. by filtration) the resulting insoluble material comprising the catalyst. The reaction mixture preferably contains from 1 to 5% of water based on the weight of methanol. The insoluble product is suitably washed with methanol after its recovery and is useful as the hydrogenation catalyst in the preparation ofα-6-deoxy-5-oxytetracycline by hydrogenation of 6-deoxy-6-demethyl-6-methylene-5-oxytetracycline or an acid addition salt or polyvalent metal salt complex thereof. Detailed examples are given for preparing the catalyst and for the production ofα-6-deoxy-5-oxytetracycline by hydrogenating 6 - dimethyl - 6- deoxy - 6 - methylene - 5 - oxytetracycline hydrochloride in the presence of the catalyst.