| 摘要 |
1418137 Preparing tetracycline compounds ANKERFARM SpA 19 Feb 1973 [24 Feb 1972] 8119/73 Heading C2C Alpha-6-deoxy-tetracyclines of Formula (II) wherein Y is hydrogen, fluorine, chlorine, bromine or iodine, and R is hydrogen, hydroxyl or a group: -O-CO-R<SP>1</SP> in which R<SP>1</SP> is C 1-6 alkyl are prepared by hydrogenating a 6-demethyl - 6 - deoxy - 6 - methylene - tetracycline of Formula (I): wherein Y and R are as defined above, at a hydrogen pressure of 1 to 150 kg./cm.<SP>2</SP> for 1-8 hours at 15‹ to 80‹ C. in a polar solvent, in the present of, as catalyst, a solution in said solvent of a complex of a ligand which is a tertiary organic phosphine, arsine or stibine with a metal which is rhodium, palladium, ruthenium, osmium, iridium, platinum or nickel, said complex containing halogen bound directly to the metal. Suitable ligands are triphenylphosphine, tributylphosphine, triethylphosphine, diethylphenylphosphine, diphenylethylphosphine, alkylphosphoric esters, triphenylstibine and triphenylarsine. The preferred metal is rhodium, the catalyst being prepared by reacting rhodium chloride with the ligand in the reaction medium. Polar solvents used are C 1-4 mono- or polyhydric alcohols, N,N<SP>1</SP>-dimethylformamide, N,N<SP>1</SP>-dimethylacetamide, dioxan, tetrahydrofuran, methoxyethanol, ethoxyethanol, acetonitrile or pyridine. |
