| 摘要 |
1340616 Kasugamycin derivatives; methyl 4-pyrimidinecarboximidate BRISTOL-MYERS CO 3 May 1971 [1 May 1970] 12812/71 Headings C2A and C2C Novel carbobenzoxy derivatives of kasugamycin having the general formula I and acid-addition salts thereof, wherein R is hydrogen or a radical of formula are prepared by reacting kasugamycin or its acid-addition salt with carbobenzoxy chloride at a pH above 7 to give a compound (Ib) having the Formula I in which R is the said radical, and if desired subjecting this compound to hydrolysis with a mild basis reagent to give a compound (Ia) having the Formula I in which R is hydrogen. The preferred salts are the mono-hydrochlorides. 1 to 10 molar equivalents of carbobenzoxy chloride are used per mole of kasugamycin and the pH may be kept above 7, preferably at pH 7 to 11, by addition of an alkali metal hydroxide in a heterogeneous aqueous-water immiscible solvent system. The hydrolysing agent used is hydrazine in an organic solvent such as a C 1 to C 4 alkanol. The inventive compounds are used for preparing semi-synthetic antibiotically active kasugamycin derivatives. For example, by reaction of compound (Ia) with (1) methyl acetamidate, and (2) 4-pyridinealdoxime or methyl-4-pyridinecarboximidate, in each case followed by catalytic hydrogenation to remove the carbobenzoxy residue, there are obtained compounds having an analogous structure to I above but wherein R is (1) acetamidino, and (2) piperidylcarboxamidino, and the carbobenzoxy-amino group is replaced by -NH 2 . Methyl 4-pyridinecarborimidate is prepared by reacting 4-cyanopyridine with sodium methoxide in methanol. Reference has been directed by the Comptroller to Specifications 1,094,566 and 1,244,026. |
