Patents by Inventor Khuong H. X. Mai

Khuong H. X. Mai 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: 5064827
    Abstract: Compounds of the present invention, are represented by the general formula ##STR1## wherein R.sub.1 group which may be alkyl of from 1 to about 6 carbon atoms, alkenyl of from 2 to about 6 carbon atoms, alkynyl of from 2 to about 10 carbon atoms, alkoxy wherein the alkyl group contains from 1 to about 6 carbon atoms, halogen, acetamido, amino, nitro, alkylamino of from 1 to about 6 carbon atoms, hydroxy, hydroxyalkyl of from 1 to about 6 carbon atoms, cyano or arylalkoxy wherein the alkyl group contains from 1 to about 6 carbon atoms R.sub.2, R.sub.3 and R.sub.4 are hydrogen or hydroxyl groups or the combination of either hydrogen or hydroxyl groups; W represents alkylene of from 1 to about 10 carbon atoms; and B represents --NHCOR.sub.5, --NHCONR.sub.5 R.sub.6, or --NHCOOR.sub.5 wherein R.sub.5 and R.sub.
    Type: Grant
    Filed: August 23, 1990
    Date of Patent: November 12, 1991
    Assignee: Du Pont Merck Pharmaceutical Company
    Inventors: Ghanshyam Patil, William L. Matier, Khuong H. X. Mai
  • Patent number: 4990668
    Abstract: Described is a process for preparing a racemic or chiral aryloxypropanolamine (1) or arylethanolamine (2) of the formula ##STR1## wherein Ar is aryl, substituted aryl, heteroaryl, or aralkyl and R is alkyl, substituted alkyl, aralkyl, or WB wherein W is a straight or branched chain alkylene of from 1 to about 6 carbon atoms and wherein B is --NR.sub.2 COR.sub.3, --NR.sub.2 CONR.sub.3 R.sub.4, --NR.sub.2 SO.sub.2 R.sub.3, --NR.sub.2 SO.sub.2 NR.sub.3 R.sub.4, or --NR.sub.2 COOR.sub.5, where R.sub.2, R.sub.3, R.sub.4, and R.sub.5 may be the same or different and may be hydrogen, alkyl, alkoxyalkyl, alkoxyaryl, cycloalkyl, alkenyl, alkynyl, aryl, heteroaryl, or aralkyl, except that R.sub.3 and R.sub.5 are not hydrogen when B is --NR.sub.2 SO.sub.2 R.sub.3 or --NR.sub.3 COOR.sub.5, or R.sub.3 and R.sub.4 may together with N form a 5- to 7-membered heterocyclic group.The process can be used to prepare beta-blocking agents, useful in the treatment of cardiac conditions.
    Type: Grant
    Filed: December 4, 1985
    Date of Patent: February 5, 1991
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: Khuong H. X. Mai, Ghanshyam Patil, William L. Matier
  • Patent number: 4966914
    Abstract: In accordance with the present invention, disclosed herein are compounds of the formula ##STR1## wherein R is hydrogen, straight or branched loweralkyl, cycloalkyl, amino, loweralkoxy or acylamino, and R.sub.1 is straight or branched loweralkyl, amino, cyclohexyl phenyl or phenyl substituted with loweralkyl, loweralkoxy or halo, benzyl, morpholino, piperidino, tetrahydrofuranyl, dihydrofuranyl, furanyl, tetrahydropyranyl, dioxolanyl, 2,2-dimethyl dioxolanyl, dioxanyl, pyrrolidinyl, tetrahydrooxazolyl, and dihydrooxazolyl, R.sub.2 is hydrogen or --COR.sub.3 wherein R.sub.3 is straight or branched loweralkyl, provided, however, when R.sub.1 is loweralkyl or cyclohexyl, R.sub.2 is not hydrogen, and pharmaceutically acceptable salts thereof. The compounds are useful in the treatment of glaucoma.
    Type: Grant
    Filed: December 15, 1988
    Date of Patent: October 30, 1990
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: Ghanshyam Patil, William L. Matier, Khuong H. X. Mai
  • Patent number: 4959390
    Abstract: Compounds of the present invention, are represented by the general formula ##STR1## wherein R.sub.1 group which may be alkyl of from 1 to about 6 carbon atoms, alkenyl of from 2 to about 6 carbon atoms, alkynyl of from 2 to about 10 carbon atoms, alkoxy wherein the alkyl group contains from 1 to about 6 carbon atoms, halogen, acetamido, amino, nitro, alkylamino of from 1 to about 6 carbon atoms, hydroxy, hydroxyalkyl of from 1 to about 6 carbon atoms, cyano or arylalkoxy wherein the alkyl group contains from 1 to about 6 carbon atoms R.sub.2, R.sub.3 and R.sub.4 are hydrogen or hydroxyl groups or the combination of either hydrogen or hydroxyl groups; W represents alkylene of from 1 to about 10 carbon atoms; and B represents --NHCOR.sub.5, --NHCONR.sub.5 R.sub.6, or --NHCOOR.sub.5 wherein R.sub.5 and R.sub.
    Type: Grant
    Filed: December 15, 1988
    Date of Patent: September 25, 1990
    Assignee: E. I. du Pont de Nemours and Company
    Inventors: Ghanshyam Patil, William L. Matier, Khuong H. X. Mai
  • Patent number: 4935422
    Abstract: Compounds of the present invention, are represented by the general formula ##STR1## wherein R represents a straight or branched loweralkyl from 1 to about 6 carbon atoms, loweralkene from 2 to about 6 carbon atoms, or ##STR2## where m is o or 1 and n is 2, 3, 4, or 5 provided that when m is o, n is 2, 3, 4, or 5 and when m is 1, n is 3 or 4, and R.sub.1 is hydrogen, a straight, branched or cyclic loweralky from 1 to about 6 carbon atoms or loweralkoxy, phenyl or substituted phenyl, and R.sub.2 represents a straight or branched loweralkyl from 1 to about 6 carbon atoms or W-B wherein W represents alkylene of from 1 to about 10 carbon atoms which may be substituted with loweralkyl of from 1 to about 4 carbon atoms; and B represents hydrogen, --NHCOR.sub.4, or --NHCONR.sub.3 R.sub.4, wherein R.sub.3 and R.sub.
    Type: Grant
    Filed: December 15, 1988
    Date of Patent: June 19, 1990
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: Ghanshyam Patil, Khuong H. X. Mai
  • Patent number: 4902831
    Abstract: Described is a process for preparing 1,2-diaminoethane having the formula ##STR1## where R.sub.1, R.sub.2, R.sub.3, and R.sub.4 are each independently hydrogen, C.sub.1 -C.sub.20 alkyl, C.sub.3 -C.sub.12 cycloalkyl, C.sub.7 -C.sub.15 aralkyl, unsubstituted or substituted aryl or heteroaryl or alternatively, R.sub.1 and R.sub.2 together with the carbon atom form a 3 to 12 member cycloalkyl group, or with a heteroatom form a 3 to 12 member heterocyclic group and R.sub.3 and R.sub.4 together with the nitrogen atom form a 3 to 12 member heterocyclic group, optionally including oxygen, sulfur or phosphorus as a second heteroatom, the process comprising: reacting a preformed Schiff base with a nitroalkane as a neat mixture in the presence of a catalytic amount of an inorganic base to form the 1-nitro-2-aminoethane intermediate, which was then hydrogenated to give 1,2-diaminoethane.
    Type: Grant
    Filed: November 9, 1987
    Date of Patent: February 20, 1990
    Assignee: E. I. Du Pont de Nemours & Co.
    Inventors: Khuong H. X. Mai, Ghanshyam Patil
  • Patent number: 4897417
    Abstract: In accordance with the present invention, disclosed herein are compounds of the formula ##STR1## wherein R is straight or branched loweralkyl, R.sub.1 is hydrogen, straight or branched loweralkyl, lowercycloalkyl, amino, loweralkoxy or acylamino, and R.sub.2 is straight or branched loweralkyl, amino, cyclohexyl, morpholino, piperidino, tetrahydrofuranyl, dihydrofuranyl, tetrahydropyranyl, dioxolanyl, 2,2-dimethyl dioxolanyl, dioxanyl, pyrrolidinyl, tetrahydrooxazolyl, and dihydrooxazolyl, and pharmaceutically acceptable salts thereof. The compounds are useful in the treatment of glaucoma.
    Type: Grant
    Filed: December 15, 1988
    Date of Patent: January 30, 1990
    Assignee: E. I. Du Pont de Nemours & Co.
    Inventors: Ghanshyam Patil, William L. Matier, Khuong H. X. Mai
  • Patent number: 4798892
    Abstract: The present invention relates to compounds of the general formula ##STR1## wherein Ar represents a substituted or unsubstituted heterocyclic group; W represents alkylene of from 1 to about 10 carbon atoms; and B represents --NR.sub.2 COR.sub.1, --NR.sub.2 CONR.sub.1 R.sub.3, --NR.sub.2 SO.sub.2 R.sub.1, NR.sub.2 SO.sub.2 NR.sub.1 R.sub.3, or --NR.sub.2 COOR.sub.1, wherein R.sub.1, R.sub.2 and R.sub.3 may be alike or different and may be hydrogen, alkyl, alkoxyalkyl cycloalkyl, alkenyl, alkynyl, aryl, heteroaryl, or aralkyl, except that R.sub.1 is not hydrogen when B is --NR.sub.2 SO.sub.2 R.sub.1 or --NR.sub.2 COOR.sub.1, or R.sub.1 and R.sub.3 may together with N form a 5 to 7 membered heterocyclic group and the pharmaceutically acceptable salts thereof. The compounds exhibit beta-adrenergic blocking activity and are also useful in the treatment of glaucoma.
    Type: Grant
    Filed: April 14, 1986
    Date of Patent: January 17, 1989
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: Sheung T. Kam, William L. Matier, Ghanshyam Patil, Khuong H. X. Mai
  • Patent number: 4764630
    Abstract: A process for the preparation of N,N'-bis-trialkylsilyl carbodiimide, according to the following schematic diagram: ##STR1## where R.sub.1, R.sub.2 and R.sub.3 are each independently hydrogen, C.sub.1 -C.sub.20 alkyl, C.sub.3 -C.sub.12 cycloalkyl, C.sub.7 -C.sub.15 aralkyl, unsubstituted or substituted aryl or heteroaryl or alternatively, R.sub.1 and R.sub.2 together with the silicon atom form a 3 to 12 member heterocyclic group, optionally including oxygen, sulfur, or phosphorus as a second heteroatom, the process comprising: reacting a trialkylsilyl cyanide with cyanamide as a neat mixture to prepare the desired N,N'-bis-trialkylsilyl carbodiimide. The reaction is practically complete in one minute. The compounds so prepared are intermediates in the preparation of polymers and precursors of carbodiimide.
    Type: Grant
    Filed: December 2, 1987
    Date of Patent: August 16, 1988
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: Khuong H. X. Mai, Ghanshyam Patil
  • Patent number: 4709042
    Abstract: Described is a process for preparing 2-(1-hydroxyalkyl)-5,5-diphenylhydantoin having the formula ##STR1## wherein R.sub.1, R.sub.2 and R.sub.3 are each independently hydrogen, C.sub.1 -C.sub.20 alkyl, C.sub.3 -C.sub.12 cycloalkyl, C.sub.7 -C.sub.15 aralkyl, unsubstituted or substituted aryl or heteroaryl or alternatively, or R.sub.1 and R.sub.2 together with the carbon atom form a 3 to 12 member cycloalkyl group, the process comprising: reacting diphenylhydantoin with an aldehyde or a ketone in the presence of a strong inorganic base; an alcohol was used as solvent to solubilize the reactants. The reaction is practically complete in 15 minutes.The compounds so prepared are intermediates in the preparation of phenyltoin prodrugs.
    Type: Grant
    Filed: September 19, 1986
    Date of Patent: November 24, 1987
    Assignee: E. I. Du Pont de Nemours & Co., (Inc.)
    Inventors: Khuong H. X. Mai, Ghanshyam Patil
  • Patent number: 4575558
    Abstract: Described is a process for preparing 2,2'-disubstituted-1,3-dioxolane-4-methanol compounds having the formula ##STR1## wherein R.sub.1 and R.sub.2 are each independently hydrogen, alkyl, cycloalkyl or R.sub.1 and R.sub.2 together with the carbon atom form a 3 to 6 member cycloalkyl group, or aryl, the process comprising: reacting D- or L-serine with a nitrosating agent in an aqueous solution in the presence of formic acid, acetic acid, or propanoic acid to prepare 2,3-dihydroxypropanoic acid (D- or L-glyceric acid), the aqueous solution comprising from about 0.1 to 0.5 liter of water per mole of the serine starting material; reacting the glyceric acid so formed with 2,2-dimethoxypropane in the presence of a loweralkyl alcohol to prepare the D- or L-glyceric acid alkyl ester which is reacted with a selected aldehyde or ketone or the acetal or ketal derivative to prepare the corresponding 1,3-dioxolane derivative.
    Type: Grant
    Filed: February 15, 1984
    Date of Patent: March 11, 1986
    Assignee: American Hospital Supply Corporation
    Inventors: Khuong H. X. Mai, Ghanshyam Patil
  • Patent number: 4551537
    Abstract: Disclosed is a process for preparing optically active alpha-aminonitriles of the formula ##STR1## by the reaction of alpha-trimethylsilyloxynitriles with optically active alpha-methylbenzylamine in the presence of a loweralkyl alcohol.In the above formula, R denotes C.sub.1 -C.sub.20 alkyl, C.sub.3 -C.sub.12 cycloalkyl, C.sub.7 -C.sub.15 aralkyl or unsubstituted or substituted aryl or heteroaryl.In general, R-alpha-methylbenzylamine gave I and III as the major and the minor products, respectively. Whereas, S-alpha-methylbenzylamine gave II and IV as the major and the minor products, respectively.The compounds so prepared are intermediates in the preparation of optically active aminoacids.
    Type: Grant
    Filed: September 26, 1984
    Date of Patent: November 5, 1985
    Assignee: American Hospital Supply Corporation
    Inventors: Khuong H. X. Mai, Ghanshyam Patil
  • Patent number: 4551526
    Abstract: Described is a process for preparing alpha-aminonitriles having the formula ##STR1## where R.sub.1, R.sub.2, R.sub.3 and R.sub.4 are each independently hydrogen, C.sub.1 -C.sub.20 alkyl, C.sub.3 -C.sub.12 cycloalkyl, C.sub.7 -C.sub.15 aralkyl, unsubstituted or substituted aryl or heteroaryl or alternatively, R.sub.1 and R.sub.2 together with the carbon atom form a 3 to 12 member cycloalkyl group, or with a heteroatom form a 3 to 12 member heterocyclic group and R.sub.3 and R.sub.4 together with the nitrogen atom form a 3 to 12 member heterocyclic group and R.sub.3 and R.sub.
    Type: Grant
    Filed: September 26, 1984
    Date of Patent: November 5, 1985
    Assignee: American Hospital Supply Corporation
    Inventors: Khuong H. X. Mai, Ghanshyam Patil