| 摘要 |
<p>The invention relates to a process for the preparation of tetracycline derivatives of formula (I), and acid addition salts thereof, wherein R stands for -CH3 or =CH2, by dehalogenating and hy drating chloromethacycline or acid addition salt thereof of formula (II), or by hydrating methacycline or acid addition salts thereof of formula (III), by a treatment with hydrogen gas in the presence of a noble metal alloy catalyst on carrier and organic solvent which comprises performing hydrating under pressure of 0.1-1.0 MPa with an alloy catalyst consisting of the alloy palladium or platinum and selenium and/or tellurium used at a ratio of 1:0.01-0.5 related to the amount of the starting tetracycline and carrying out, if desired dehalogenation and hydration in one step.</p> |
