Patents Represented by Attorney Irvin N. Feit

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  • Cephalosporin derivatives
    Patent number: 4434287
    Abstract: The invention concerns a process for the manufacture of 7.beta.-amino-3-cephem-3-ol-4-carboxylic acid compounds by ring closure of esters of 2-[4-(substituted-thio)-3-acylamino-2-oxoazetidin-1-yl]-3-substituted-amin o-crotonic acids and solvolyzing the enamino group in the resulting 7.beta.-acylamino-3-substituted-amino-cephem-4-carboxylic acid esters.
    Type: Grant
    Filed: November 19, 1981
    Date of Patent: February 28, 1984
    Assignee: Ciba-Geigy Corporation
    Inventors: Robert B. Woodward, Hans Bickel