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).
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Patent number: 5064827Abstract: 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: GrantFiled: August 23, 1990Date of Patent: November 12, 1991Assignee: Du Pont Merck Pharmaceutical CompanyInventors: Ghanshyam Patil, William L. Matier, Khuong H. X. Mai
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Patent number: 4990668Abstract: 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: GrantFiled: December 4, 1985Date of Patent: February 5, 1991Assignee: E. I. Du Pont de Nemours and CompanyInventors: Khuong H. X. Mai, Ghanshyam Patil, William L. Matier
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Patent number: 4966914Abstract: 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: GrantFiled: December 15, 1988Date of Patent: October 30, 1990Assignee: E. I. Du Pont de Nemours and CompanyInventors: Ghanshyam Patil, William L. Matier, Khuong H. X. Mai
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Patent number: 4959390Abstract: 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: GrantFiled: December 15, 1988Date of Patent: September 25, 1990Assignee: E. I. du Pont de Nemours and CompanyInventors: Ghanshyam Patil, William L. Matier, Khuong H. X. Mai
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Patent number: 4935422Abstract: 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: GrantFiled: December 15, 1988Date of Patent: June 19, 1990Assignee: E. I. Du Pont de Nemours and CompanyInventors: Ghanshyam Patil, Khuong H. X. Mai
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Patent number: 4902831Abstract: 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: GrantFiled: November 9, 1987Date of Patent: February 20, 1990Assignee: E. I. Du Pont de Nemours & Co.Inventors: Khuong H. X. Mai, Ghanshyam Patil
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Patent number: 4897417Abstract: 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: GrantFiled: December 15, 1988Date of Patent: January 30, 1990Assignee: E. I. Du Pont de Nemours & Co.Inventors: Ghanshyam Patil, William L. Matier, Khuong H. X. Mai
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Patent number: 4798892Abstract: 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: GrantFiled: April 14, 1986Date of Patent: January 17, 1989Assignee: E. I. Du Pont de Nemours and CompanyInventors: Sheung T. Kam, William L. Matier, Ghanshyam Patil, Khuong H. X. Mai
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Patent number: 4764630Abstract: 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: GrantFiled: December 2, 1987Date of Patent: August 16, 1988Assignee: E. I. Du Pont de Nemours and CompanyInventors: Khuong H. X. Mai, Ghanshyam Patil
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Patent number: 4709042Abstract: 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: GrantFiled: September 19, 1986Date of Patent: November 24, 1987Assignee: E. I. Du Pont de Nemours & Co., (Inc.)Inventors: Khuong H. X. Mai, Ghanshyam Patil
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Patent number: 4575558Abstract: 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: GrantFiled: February 15, 1984Date of Patent: March 11, 1986Assignee: American Hospital Supply CorporationInventors: Khuong H. X. Mai, Ghanshyam Patil
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Patent number: 4551537Abstract: 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: GrantFiled: September 26, 1984Date of Patent: November 5, 1985Assignee: American Hospital Supply CorporationInventors: Khuong H. X. Mai, Ghanshyam Patil
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Patent number: 4551526Abstract: 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: GrantFiled: September 26, 1984Date of Patent: November 5, 1985Assignee: American Hospital Supply CorporationInventors: Khuong H. X. Mai, Ghanshyam Patil