Patents by Inventor Seyed Mehdi Tavana

Seyed Mehdi Tavana 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).

  • Chemical process
    Patent number: 6342630
    Abstract: A process for the purification of a compound of general formula I: wherein: R1 is hydrogen or C1-C6 alkyl, C2-C6 alkenyl or C2-C6 alkynyl (any of which may optionally be substituted with one or more substituents selected from halogen and OH) or COOR4, COR6, CONR4R5 or CONHSO2R4; R4 and R5 are each independently hydrogen or C1-C4 alkyl optionally substituted with one or more halogen atoms; R6 is a halogen atom or a group R4; R2 is hydrogen or halo; R3 is C1-C4 alkyl, C2-C4 alkenyl or C2-C4 alkynyl, any of which may optionally be substituted with one or more halogen atoms, or halo; or, where appropriate, a salt thereof; from a mixture containing the compound of general formula I together with one or more isomers or di-nitrated analogues thereof; the process comprising dissolving the mixture in a suitable crystallisation solvent and recrystallising the product from the resulting crystallisation solution; characterised in that the crystallisation solution contains not more than 25% loadin
    Type: Grant
    Filed: September 11, 1996
    Date of Patent: January 29, 2002
    Assignee: Zeneca Limited
    Inventors: Stephen Martin Brown, Brian David Gott, Thomas Gray, Seyed Mehdi Tavana
  • Purification process
    Patent number: 6072080
    Abstract: A process for the purification of a compound of general formula I: ##STR1## wherein R.sup.1 is hydrogen or C.sub.1 -C.sub.6 alkyl, C.sub.2 -C.sub.6 alkenyl or C.sub.2 -C.sub.6 alkynyl, any of which may optionally be substituted with one or more substituents selected from halogen and hydroxy; or COOR.sup.4, COR.sup.6, CONR.sup.4 R.sup.5 or CONHSO.sub.2 R.sup.4 ;R.sup.4 and R.sup.5 independently represent hydrogen or C.sub.1 -C.sub.4 alkyl optionally substituted with one or more halogen atoms;R.sup.6 is a halogen atom or a group R.sup.4 ;R.sup.2 is hydrogen or halo; andR.sup.3 is C.sub.1 -C.sub.4 alkyl, C.sub.2 -C.sub.4 alkenyl or C.sub.2 -C.sub.
    Type: Grant
    Filed: March 12, 1998
    Date of Patent: June 6, 2000
    Assignee: Zeneca Limited
    Inventors: Louie Akos Nady, Seyed Mehdi Tavana, Thomas Gray, Stephen Martin Brown, Brian David Gott
  • Purification process
    Patent number: 5910604
    Abstract: A process for the purification of a compound of general formula I: ##STR1## wherein R.sup.1 is hydrogen or C.sub.1 -C.sub.6 alkyl, C.sub.2 -C.sub.6 alkenyl or C.sub.2 -C.sub.6 alkynyl, any of which may optionally be substituted with one or more substituents selected from halogen and hydroxy; or COOR.sup.4, COR.sup.6, CONR.sup.4 R.sup.5 or CONHSO.sub.2 R.sup.4 ;R.sup.4 and R.sup.5 independently represent hydrogen or C.sub.1 -C.sub.4 alkyl optionally substituted with one or more halogen atoms;R.sup.6 is a halogen atom or a group R.sup.4 ;R.sup.2 is hydrogen or halo; andR.sup.3 is C.sub.1 -C.sub.4 alkyl, C.sub.2 -C.sub.4 alkenyl or C.sub.2 -C.sub.
    Type: Grant
    Filed: March 13, 1997
    Date of Patent: June 8, 1999
    Assignee: Zeneca Limited
    Inventors: Stephen Martin Brown, Brian David Gott, Thomas Gray, Seyed Mehdi Tavana