| 摘要 |
The following processes for the debromination of the 6 position of penicillin comprises a) 6-monobromopenicillin of the formula (I) is produced by treatment of the 6,6-dibromopenicillin (II) with one molar equiv. of a bisulphite salt in an inert aq. solvent at 0.100 deg. C. In the formulae n = 0, 1 or 2; R8 = H, conventional carboxy protecting gp. removable by hydrogenolysis or conventional ester forming gp.,hydrolysable under physiological conditions. 2) 6-Unsubstd. penicillins of the formula (III) are prepd. by either treating cpd. (I) with one molar equiv. of a bisulphite salt or cpd. (II) with two molar equiv. of a bisulphite salt at 50 to 100 deg. C. in an aq. solvent. In (III) R6 = H or a conventional carboxy protecting gp. removable by hydrogenolysis. 3) 6 alpha or beta hydroxyaminomethylpenicillins (IV) are prepd. by debromination of 6 alpha-hydroxyaminomethyl- 6 beta-bromopenicillin derivs. of the formula (V) with one molar equiv. of a bisulphite salt in an inert aq. solvent at 50-100 deg. C. R = 1-4 C alkyl or benzyl. - The products are beta-lactamase inhibitors and intermediates for other penicillins. EPAB- EP-129360 B A process for the preparation of a compound of the formulae (I), (III) or (VI) wherein n is 0, 1 or 2, R8 is hydrogen, a conventional carboxy protecting group removable by hydrogenolysis or a conventional ester forming radical which is hydrolysable under physiological conditions; R6 is hydrogen or a conventional carboxy protecting group removable by hydrgenolysis; and R is (C1-C4) alkyl or benzyl; which comprises treatment of a compound of the formula (II), (IV), (V) or (VII) respectively, wherein R8, R6 and R as previously defined with (a) substantially are molar equivalent, (b) at least one or at least two molar equivalents, depending on wehther a compound of formula (IV) or (V) is treated, or (c) at least one molar equivalent, respectively of a bisulphite salt in a reaction-inert aqueous solvent at a temperature in the range 0-100 Deg.C for (a) or 50-100 deg.C for (b) or (c) respectively.
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