Patents by Inventor Tim F. Tam

Tim F. Tam 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: 6476229
    Abstract: The present invention relates to a novel process for the preparation of 3-hydroxy-N,1,6-trialkyl-4-oxo-1,4-dihydropyridine-2-carboxamide of formula I: The method comprises of the TEMPO oxidation of a primary alcohol of 3-O-protected-2-hydroxymethyl-6-alkyl-4H-pyran-4-one of formula III to 3-O-protected-6-alkyl-4-oxo-4H-pyran-2-carboxylic acid of formula II. Reaction of compound of formula II with methylamine and 1,1-carbonyldiimidazole in an inert solvent affords 3-O-protected-N, 1,6-trialkyl-4-oxo-1,4-dihydropyridine-2-carboxamide, which is deprotected to give of 3-hydroxy-N,1,6-trialkyl-4-oxo-1,4-dihydropyridine-2-carboxamide of formula I.
    Type: Grant
    Filed: March 19, 2002
    Date of Patent: November 5, 2002
    Assignee: Apotex, Inc.
    Inventors: Tim F. Tam, Wanren Li
  • Patent number: 6472532
    Abstract: The present invention relates to a novel process for the preparation of 3-hydroxy-N,1,6-trialkyl-4-oxo-1,4-dihydropyridine-2-carboxamide of formula I: The method comprises of the TEMPO oxidation of a primary alcohol of 3-O-protected-2-hydroxymethyl-6-alkyl-4H-pyran-4-one of formula III to 3-O-protected-4-alkyl-4-oxo-4H-pyran-2-carboxylic acid of formula II. Reaction of compound of formula II with methylamine and 1,1-carbonyidiimidazole in an inert solvent affords 3-O-protected-N,1,6-trialkyl-4-oxo-1,4-dihydropyridine-2-carboxamide, which is deprotected to give of 3-hydroxy-N,1,6-trialkyl-4-oxo-1,4-dihydropyridine-2-carboxamide of formula I.
    Type: Grant
    Filed: March 19, 2002
    Date of Patent: October 29, 2002
    Assignee: Apotex, Inc.
    Inventors: Tim F. Tam, Wanren Li
  • Patent number: 6426418
    Abstract: The present invention relates to a novel process for the preparation of 3-hydroxy-N,1,6-trialkyl-4-oxo-1,4-dihydropyridine-2-carboxamide of formula I: The method comprises of the TEMPO oxidation of a primary alcohol of 3-O-protected-2-hydroxymethyl-6-alkyl-4H-pyran-4-one of formula III to 3-O-protected-6-alkyl-4-oxo-4H-pyran-2-carboxylic acid of formula II. Reaction of compound of formula II with methylamine and 1,1-carbonyldiimidazole in an inert solvent affords 3-O-protected-N,1,6-trialkyl-4-oxo-1,4-dihydropyridine-2-carboxamide, which is deprotected to give of 3-hydroxy-N,1,6-trialkyl-4-oxo-1,4-dihydropyridine-2-carboxamide of formula I.
    Type: Grant
    Filed: November 2, 2001
    Date of Patent: July 30, 2002
    Assignee: Apotex, Inc.
    Inventors: Tim F. Tam, Wanren Li
  • Patent number: 6114537
    Abstract: Thiols are trapped, and converted to disulfide compounds, by a process of reacting them with compounds containing a 1,2,4-thiadiazole ring structure carrying a substituent at position 3 of the thiadiazole ring, and being unsubstituted at position N-2. The process is useful pharmacologically, in inhibiting certain thiol-containing enzymes such as H.sup.+ /K.sup.+ -ATPase (the proton pump), and industrially, in selective removal of thiol compounds from gas or liquid mixtures.
    Type: Grant
    Filed: February 21, 1997
    Date of Patent: September 5, 2000
    Assignee: Apotex Inc.
    Inventors: Khashayar Karimian, Tim F. Tam, Denis Desilets, Sue Lee, Tullio Cappelletto, Wanren Li
  • Patent number: 6093738
    Abstract: Novel thiadiazole compounds are provided, which are effective as proton pumps inhibitors, useful in treating peptic ulcers by inhibition of the proton pump enzyme H.sup.+ /K.sup.+ -ATPase. The compounds are 3-substituted 1,2,4-thiadiazolo [4,5-.alpha.]benzimidazole and 3-substituted imidazo[1,2-d]-1,2,4-thiadiazoles corresponding to the general formula: ##STR1## where X and Z either represent an optionally substituted benzene ring fused to the diazole nucleus, or represent a variety of independent chemical groupings (hydrogen, lower alkyl, halo, etc.) and Y is selected from a wide range, e.g. heterocyclics and carbonyl groups.
    Type: Grant
    Filed: February 21, 1997
    Date of Patent: July 25, 2000
    Inventors: Khashayar Karimian, Tim F. Tam, Denis Desilets, Sue Lee, Tullio Cappelletto, Wanren Li
  • Patent number: 6063933
    Abstract: The present invention relates to a process to prepare a compound of formula (I) wherein Y and Z can be identical or different and represent a halogene. The bis-triazole compounds of formula (I) and intermediates have antifungal activity.
    Type: Grant
    Filed: February 24, 1998
    Date of Patent: May 16, 2000
    Assignees: Khashayar Karimian, Tim F. Tam, John F. Braganza, Yuri Goldberg, Salvatore Zinghini
    Inventors: Khashayar Karimian, Tim F. Tam, John F. Braganza, Yuri Goldberg, Salvatore Zinghini
  • Patent number: 5677302
    Abstract: Novel thiadiazole compounds are provided, which are effective as proton pumps inhibitors, useful in treating peptic ulcers by inhibition of the proton pump enzyme H.sup.+ /K.sup.+ -ATPase. The compounds are 3-substituted 1,2,4-thiadiazolo ?4,5-.alpha.!benzimidazole and 3-substituted imidazo?1,2-d!-1,2,4-thiadiazoles corresponding to the general formula: ##STR1## where X and Z either represent an optionally substituted benzene ring fused to the diazole nucleus, or represent a variety of independent chemical groupings (hydrogen, lower alkyl, halo, etc.) and Y is an electronegative group.
    Type: Grant
    Filed: February 26, 1996
    Date of Patent: October 14, 1997
    Assignee: Apotex Inc.
    Inventors: Khashayar Karimian, Tim F. Tam, Denis Desilets, Sue Lee, Tullio Cappelletto, Wanren Li
  • Patent number: 4602006
    Abstract: Compounds of the formula ##STR1## wherein n is 1-3; R.sup.1, R.sup.2 and R.sup.3 are the same or different and are hydrogen, lower alkyl, lower alkenyl, lower alkynyl, aryl or aryl lower alkyl wherein when aryl is phenyl it is unsubstituted or independently substituted with one or more halo, lower alkyl or lower alkoxy groups; and R.sup.4 is hydrogen, lower alkyl, lower alkenyl, lower alkynyl, trialkylsilyl, aryl or aryl lower alkyl wherein when aryl is phenyl it is unsubstituted or independently substituted by one or more halo, lower alkyl or lower alkoxy groups; excluding those compounds wherein R.sup.1 and R.sup.2 are hydrogen and R.sup.4 is ethyl, propyl or butyl. These compounds are useful as protease inhibitors.
    Type: Grant
    Filed: May 9, 1984
    Date of Patent: July 22, 1986
    Assignee: Syntex (U.S.A.) Inc.
    Inventors: Alexander Krantz, Tim F. Tam, Robin W. Spencer