| 摘要 |
<p>NEW MATERIAL:A compound shown by the formulaI(R<1> and R<2> is H or methyl). EXAMPLE:6-O-Methylerythromycin B. USE:An antibacterial agent showing improved antibacterial activity in living body. PROCESS:Erythromycin A is gradually added to a mixture of carbobenzoxy chloride and sodium hydrogencarbonate, they are reacted at room temperature -60 deg.C with vigorous stirring for 1-3hr, and the reaction product is purified to give 2'-O-benzyloxycarbonyl-N-benzyloxycarbonyl-des-N-methylerythromycin B. This compound is reacted with a methylating agent in the presence of a base such as an alkali metal hydroxide, etc., so that the hydroxyl groups at 6-, 11- and 4''-positions of the compound are methylated to give a compound shown by the formula II, which is reduced catalytically so that benzyloxycarbonyl group a protecting group is eliminated, and reduced catalytically in the presence of excess formaldehyde so that it is N-methylated, to give a compound shown by the formulaI.</p> |
