5187-94-0Relevant articles and documents
Silylation process
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, (2008/06/13)
A process for the silylation of 6-aminopenicillanic acid or 7-amino-desacetoxy-cephalosporanic acid by silylation in certain carboxylic acid esters and its use in the production of 6-alpha-aminoacyl-penicillins and 7-alpha-aminoacyl-desacetoxy-cephalosporins.
Pharmaceutical tablet, pharmaceutical granulate and process for their preparation
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, (2008/06/13)
A pharmaceutical tablet containing an amphoteric beta-lactam antibiotic, microcrystalline or micro fine cellulose or a mixture of both and a second disintegrant, being low-substituted hydroxypropylcellulose, which fully disintegrates in water within 60 seconds. When swallowed it shows a bioavailability as good as a pharmacy prepared suspension of the antibiotic. The tablet is compressed from a mixture containing a new granulate which is prepared from the antibiotic substance, microcrystalline and/or micro fine cellulose and water only. Such tablets can also be prepared by using other known tablet disintegrants as the second disintegrant.
Manufacture of semi-synthetic penicillin antibiotics
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, (2008/06/13)
Improvements in or relating to the manufacture of semi-synthetic penicillin antibiotics are described. More particularly an improved process for the preparation of a 6β-acylamino penicillanic acid antibiotic product is described in which 6β-aminopenicillanic acid (6-APA) is reacted in an inert solvent with a silylating agent to form a silylated compound of formula (I) STR1 wherein R1 represents a hydrogen atom or a tri(C1-6 alkyl)silyl group, and R2 represents a tri(C1-6 alkyl)silyl group and the compound of formula (I) is thereafter contacted with an acyl chloride or protected acyl chloride corresponding to the desired 6β-acylamino group, the silyl groups are cleaved and the desired antibiotic product is recovered, silylation being effected using a tri(C1-6 alkyl) silylurea or tri(C1-6 alkyl) halosilane and the compound of formula (I) produced being reacted without intermediate isolation with the acyl chloride or protected acyl chloride, wherein acylation is effected in the presence of a hydrogen halide acceptor mixture comprising in excess of 0.15 and preferably up to 3.00 moles of urea per mole of 6-APA; in excess of 0.15, and preferably up to 1.30 moles of bis-tri-(C1-6 alkyl)silylurea per mole of 6-APA; and in excess of 0.25, and preferably up to 3.30 moles of tri-(C1-6 alkyl)-ammonium halide per mole of 6-APA. The process is especially useful for the preparation of ampicillin and amoxycillin in high yield and high purity.
