Patents by Inventor Richard Dappen

Richard Dappen 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: 4997966
    Abstract: A compound of formula I ##STR1## wherein R.sub.1 is C.sub.1 -C.sub.4 alkyl, phenyl or benzyl,R.sub.2 is C.sub.1 -C.sub.4 alkyl, phenyl or benzyl,a is 0, 1 or 2,R.sub.3 is linear or branched unsubstituted or OH-substituted C.sub.1 -C.sub.12 alkylene or is phenylene,R.sub.5 is the divalent radical, diminished by the --CO--O group, of a lactone having a total of 4 to 7 ring members and containing at least one chiral carbon atom and corresponding predominantly to an optically active enantiomeric form,R.sub.4 is a direct bond, C.sub.1 -C.sub.4 alkyl--CH or CF.sub.3 --CH, andY is phenyl, naphthyl, fluorenyl or anthryl, each unsubstituted or substituted by C.sub.1 -C.sub.12 alkyl, C.sub.1 -C.sub.12 alkoxy, halogen, --CN or --NO.sub.2.These compounds are suitable for the preparation of stationary phases for the chromatographic separation of chiral compounds.
    Type: Grant
    Filed: December 7, 1989
    Date of Patent: March 5, 1991
    Assignee: Ciba-Geigy Corporation
    Inventors: Dieter Lohmann, Richard Dappen
  • Patent number: 4997965
    Abstract: Compounds of formula I ##STR1## wherein R.sub.1 is C.sub.1 -C.sub.4 alkyl, phenyl or benzyl,R.sub.2 is C.sub.1 -C.sub.4 alkyl, phenyl or benzyl,a is 0, 1 or 2,R.sub.3 is linear or branched unsubstituted or OH-substituted C.sub.1 -C.sub.12 alkylene or is phenylene,X is --O--, --X-- or --NR.sub.6, wherein R.sub.6 is H, C.sub.1 -C.sub.4 alkyl or --CO--R.sub.5 --OH,b is 0, orb is an integer from 1 to 6 and R.sub.4 is linear or branched unsubstituted or OH-substituted C.sub.1 -C.sub.12 alkylene,Y is --O--, --S-- or --NR.sub.7, wherein R.sub.7 is H or C.sub.1 -C.sub.4 alkyl,R.sub.5 is the divalent radical, diminished by the --CO--O group, of a lactone having a total of 4 to 7 ring members and containing at least one chiral carbon atom and corresponding predominantly to an optically active enantiomeric form, and e is an integer from 1 to 10.These compounds are suitable for the preparation of stationary phases for the chromatographic separation of chiral compounds.
    Type: Grant
    Filed: December 4, 1989
    Date of Patent: March 5, 1991
    Assignee: Ciba-Geigy Corporation
    Inventors: Dieter Lohmann, Richard Dappen