| 摘要 |
Azinomethyl-rifamycins I <IMAGE> (I) (wherein Y=H or COCH3 and either R1=C1-C7 alkyl or C3-C4 alkenyl and R2=C1-C7 alkyl, C2-C4 cloro-, hydroxy-, or alkoxy-alkyl C3-C4 alkenyl, cycloalkyl having a C3-C7 ring, cycloalkylalkyl having a C3-C6 ring, phenyl or C7-C8 aralkyl optionally monohalogen substituted in the aryl group or NR1R2= a cyclic moiety, said moiety being pyrrolidinyl, piperidinyl, hexahydroazepinyl or heptahydroazocinyl, each of which are unsubstituted or substituted with 1 or 2 methyl radicals, 4-alkyl-1-piperazinyl, morpholinyl or 1,2,3,4-tetrahydroisoquinolinyl) are prepared from rifamycin S by (a) dissolving the rifamycin S in tetrahydrofuran, CHCl3, dioxan, CH2Cl2 or dichloroethane (b) adding (i) a Schiff's base CH2=NR3 wherein R3= t-alkyl or (ii) a compound R4N(CH2OR5)2 wherein R4=lower alkyl, lower alkenyl, cycloalkyl having a C5-C6 ring, phenyl, benzyl or alpha - or beta -phenethyl and R5=H or lower alkyl or (iii) a compound <IMAGE> wherein R6=C1-C6 alkyl, cycloalkyl having a C5-C6 ring or alkenyl (c) adding hydrazine and (d) adding a chloroformiminium chloride <IMAGE> wherein R1 and R2 are as above defined.
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