Patents by Inventor Jan Vijn

Jan Vijn 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).

  • Methods for the preparation of (3R,3aS,6aR) hexahydro-furo[2,3-b]furan-3-ol
    Patent number: 7595408
    Abstract: The present invention relates to methods for the preparation of diastereomerically pure (3R,3aS,6aR) hexahydro-furo[2,3-b]furan-3-ol as well as a novel intermediate, (3aR,4S,6aS) 4-methoxy-tetrahydro-furo[3,4-b]furan-2-one for use in said methods. More in particular the invention relates to a stereoselective method for the preparation of diastereomerically pure (3R,3aS,6aR) hexahydro-furo[2,3-b]furan-3-ol, as well as methods for the crystallization of (3aR,4S,6aS) 4-methoxy-tetrahydro-furo[3,4-b]furan-2-one and for the epimerization of (3aR,4R,6aS) 4-methoxy-tetrahydro-furo[3,4-b]-furan-2-one to (3aR,4S,6aS) 4-methoxy-tetrahydro-furo[3,4-b]furan-2-one.
    Type: Grant
    Filed: March 31, 2005
    Date of Patent: September 29, 2009
    Assignee: Tibotec Pharmaceuticals, Ltd.
    Inventors: Peter Jan Leonard Mario Quaedflieg, Bart Rudolf Romanie Kesteleyn, Robert Jan Vijn, Constantinus Simon Maria Liebregts, Jacob Hermanus Matheus Hero Kooistra, Franciscus Alphons Marie Lommen
  • Process for the preparation of (S)-glyceraldehyde acetonide
    Patent number: 7361775
    Abstract: The invention relates to a process for the preparation of (S)-glyceraldehyde acetonide in aqueous solution from 3,4-O-isopropylidene-L-threonic acid or a salt thereof in aqueous solution, and hypochlorite in aqueous solution wherein the aqueous hypochlorite solution has a pH>7.5 and wherein during addition of at least 0.1 molar equivalents of hypochlorite based on the amount of 3,4-O-isopropylidene-L-threonic acid, an acid solution is not simultaneously added. The invention also relates to a process according to the invention, wherein 3,4-O-isopropylidene-L-threonic acid or a salt thereof is prepared from 5,6-O-isopropylidene-L-ascorbic acid or a salt thereof in the presence of H2O2 and a base in a manner known per se, wherein excess H2O2 is optionally removed by catalase.
    Type: Grant
    Filed: October 7, 2004
    Date of Patent: April 22, 2008
    Assignee: DSM IP Assets B.V.
    Inventors: Peter Jan Leonard Mario Quaedflieg, Franciscus Alphons Marie Lommen, Robert Jan Vijn, Danniël Adrianus Franciscus Jacobus Boxtel Van
  • Storable water-silica suspensions and methods
    Publication number: 20050038127
    Abstract: Storable water-silica suspensions and methods of cementing well bores are provided. The storable water-silica suspensions are basically comprised of water, silica and an effective amount of a suspending agent selected from the group consisting of colloidal materials, clays and gel forming polymers.
    Type: Application
    Filed: September 29, 2004
    Publication date: February 17, 2005
    Inventors: Jan Vijn, Bach Dao
  • Storable water-microsphere suspensions for use in well cements and methods
    Publication number: 20050011412
    Abstract: Storable water-microsphere suspensions for use in well cements and methods of cementing well bores are provided. The storable water-microsphere suspensions comprise water, microspheres and an effective amount of a suspending agent selected from the group consisting of microfine or colloidal materials and gel forming polymers.
    Type: Application
    Filed: August 18, 2004
    Publication date: January 20, 2005
    Inventors: Jan Vijn, Bach Dao