Process for introducing an oxygen-containing functional group into ansamycins
AssigneeCiba-Geigy Corporation
InventorWilhelm Kump
Life of this patent
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Abstract
3-Hydroxyrifamycin S and its new analogues with an etherified or esterified 3-hydroxyl group of the formula ##STR1## in which each of R and R' represents a hydrogen atom, or R' represents acetyl and R represents hydrogen, an optionally substituted hydrocarbyl or the acyl radical of a carboxylic acid, and also the corresponding compounds of the SV series, are obtained by a novel process in which 3-bromorifamycin S is treated with a reagent ROH, in which R has the meanings mentioned above, or with a salt thereof, in a neutral to weakly basic medium. The final products are primarily suitable as antibiotics for combating microbial infections and/or as intermediates for the manufacture of the same.
Claims13
Process for the production of a rifamycine derivative of the S series of the formula ##STR6## in which each of R and R' represents a hydrogen atom, or R' represents acetyl and R represents hydrogen, a radical Alk or a radical Ar or the acyl radical R.sup.2 --(C.dbd.O)-- which R.sup.2 is hydrogen, Alk or Ar, whereby Alk represents an alkyl radical having a maximum of 7 carbon atoms or such an alkyl substituted with hydroxy or alkoxy having a maximum of 4 carbon atoms, and Ar represents phenyl or a phenyl substituted with lower alkyl, lower alkoxy, methylendioxy or formyl, or of an analogous derivative of the SV series, wherein 3-bromorifamycin S of the formula ##STR7## is treated with a compound of the formula ROH (III) in which R has the meanings mentioned above, or with a salt thereof, in a neutral to basic medium not exceeding pH 10.0 and, optionally, in the presence of a hydrogen bromide-binding agent and/or an organic solvent, at atmospheric or slightly elevated pressure and temperatures between +20.degree. to +140.degree., and the product is isolated in the form of a derivative of the S series of SV series.
A rifamycin S derivative of the formula ##STR8## in which each of R and R' represents a hydrogen atom or
- R' represents acetyl and R represents a radical Alk or a radical Ar or the acyl radical of a carboxylic acid R.sup.2 --(C.dbd.O)-- in which R.sup.2 is hydrogen, Alk or Ar, whereby Alk represents an alkyl radical having a maximum of 7 carbon atoms or such an alkyl substituted with hydroxy or alkoxy having a maximum of 4 carbon atoms, and Ar represents phenyl or a phenyl substituted with lower alkyl, lower alkoxy, methylendioxy or formyl,
- and a corresponding derivative of the SV series.
Dependencies are inferred from the claim text.