Patents by Inventor Hans-Jurgen Federsel

Hans-Jurgen Federsel has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 6414141
    Abstract: Applicants have developed a process for purifying an ampicillin pro-drug ester, e.g., bacampicillin, or an acid addition salt thereof of formula I. The process comprises a step wherein a crude solution of the pro-drug ester is subjected to an evaporation which is controlled by the evaporation rate of the organic solvent such that a continuous operation is accomplished for the crystallization of the desired purified pro-drug ester or salt thereof. Said crystallization is preferably preceded by an aqueous phase extraction and/or an organic phase extraction, both preferably also being performed continuously.
    Type: Grant
    Filed: January 26, 1999
    Date of Patent: July 2, 2002
    Assignee: AstraZeneca AB
    Inventors: Hans-Jürgen Federsel, Erik Könberg
  • Patent number: 5300660
    Abstract: Stereoconservative method for preparation of an (R)- or (S)-isomer of the compound of the formula I with at least 95% optical purity ##STR1## wherein R.sup.1 is a hydrogen atom, a saturated or unsaturated lower alkyl group, a cycloalkyl group, or a group (CH.sub.2).sub.m Ph wherein m is 0-3 and Ph is a substituted or unsubstituted phenyl group including1) O,N-dialkylation, directly or stepwise of (R)- or (S)-proline2) aminolysis3) reduction to formation of the (R)- or (S)-isomer of the compound of the formula I, and new intermediates II and III in optical active form obtained by the reaction steps above and wherein R.sup.2 is defined as R.sup.1 above.
    Type: Grant
    Filed: November 12, 1992
    Date of Patent: April 5, 1994
    Assignee: Astra Lakemedel Aktiebolag
    Inventors: Hans-Jurgen Federsel, Thomas Hogberg, Sten I. Ramsby, Hans E. P. Strom