Amoxycillin and analogues prepn. - by reaction of 6-APA with mixed acid anhydrides prepd. from chlorocarbonyl(or sulphiinyl) oxy-NN-dimethylformiminium chlorides

摘要

Prepn. of penicillins of formula (I): (where 6-APA is the 6-aminopenicillamic acid residue; and X is H or Cl); comprises (i) firstly reacting 6-APA, or a salt of the CO2H gp., with a cpd. of (where Y is Cl, Br or I; A is C or S; R is alkyl, benzyl or phenyl); (ii) replacing the halogen Y with NH2 by reaction with NH3; and (iii) reducing with H2 the product of the second stage to give I. Amoxycillin and its analogues are prepd. without the need to protect the NH2 gp. of alpha-aminophenylacetic acids. Cpd. II is prepd. by reaction of COCl2 or SOCl2 with DMF and reacting the inter: with the phenylacetic acids or their salts.