Abstract: The present invention relates to a novel process for the preparation of a cefdinir by reacting O-acetyl thioester of Formula I with in the presence of a base in suitable solvent wherein R? represents H or any carboxyl protecting group, and then converting to the cefdinir by the removal of protecting groups. This invention also relates to making the cefdinir using a novel process to prepare the O-acetyl thioester intermediate (Formula I) by condensing (Z)-2-(2-amino-4-thiazolyl)-2-acetyloxyiminoacetic acid with bis(benzothiazol-2-yl)disulphide in the presence of triphenylphosphine and a base in a suitable solvent.