Patents by Inventor Venkataraman Ramachandran
Venkataraman Ramachandran 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: 11943094Abstract: A method includes allocating an identifier to each of a plurality of policies each comprising a network-isolation identifier associated with a VXWAN directive and transmitting each of the plurality of policies to one or more devices in a network.Type: GrantFiled: June 10, 2021Date of Patent: March 26, 2024Assignee: Palo Alto Networks, Inc.Inventors: Kumar Ramachandran, Venkataraman Anand, Navneet Yadav, Arivu Ramasamy, Aaron Edwards
-
Patent number: 5847225Abstract: A mixture formed from 2-naphthaldehyde (e.g., 6-methoxy-2-naphthaldehyde) and a dihydrocarbyl ketone having at least one hydrogen atom in the .alpha.-position (e.g., acetone) is heated in the presence of a heterogeneous basic catalyst (e.g., basic alumina) such that the unsaturated 2-naphthyl ketone is formed. The unsaturated ketone can be hydrogenated using, for example, a Pd/C catalyst to form the corresponding saturated ketone. The process enables efficient production of nabumetone and related pharmaceuticals by a clean reaction.Type: GrantFiled: April 25, 1997Date of Patent: December 8, 1998Assignee: Albemarle CorporationInventors: Venkataraman Ramachandran, Stephen E. Belmont
-
Patent number: 5705039Abstract: Impure 2,6-diisopropylphenol (DIP) is purified by use of a distillation process in which a single distillation column is used. The process comprises: (a) subjecting the impure DIP to a first continuous distillation in the column in an inert environment to distill off lower boiling components and produce first column bottoms enriched in DIP; (b) collecting, cooling and storing the first column bottoms while continuously maintaining them in an inert environment; (c) discontinuing the first continuous distillation; (d) subjecting the first column bottoms to a second continuous distillation in an inert environment in the same column to produce a second overhead distillate composed of purified DIP. The process avoids the formation in the distilling mixtures of dose boiling impurities due to seepage of air through standard pipe flanges and fittings and consequent oxidation reactions which occur under the conditions needed for batch distillations conducted in typical industrial distillation facilities.Type: GrantFiled: October 13, 1995Date of Patent: January 6, 1998Assignee: Albemarle CorporationInventors: Sam F. Clarke, Venkataraman Ramachandran, J. Steve Staton, Paul L. Wiggins
-
Patent number: 5591311Abstract: A process for purifying impure 2,6-diisopropylphenol (DIP) mixtures having lower and higher boiling phenolic impurities is described. The process involves washing the mixture with aqueous alkali metal hydroxide solution in an inert atmosphere and separating the aqueous and organic phases, washing the resulting organic phase with water, and then subjecting the water-washed organic phase to distillation in an inert environment to recover purified DIP. Since only one distillation is required rather than two, the development of impurities in the DIP caused by in situ oxidation reactions at elevated temperatures due to the inevitable presence of traces of air in commercial distillation facilities is reduced to acceptable levels.Type: GrantFiled: October 26, 1995Date of Patent: January 7, 1997Assignee: Albemarle CorporationInventor: Venkataraman Ramachandran
-
Patent number: 5574183Abstract: A process for the separation of a racemic mixture of certain aliphatic carboxylic acids or esters thereof is disclosed. The process comprises i) forming a diastereomeric salt by reaction comprising said racemic mixture of a C.sub.1 to C.sub.6 linear or branched aliphatic carboxylic acid and an amount of a chiral organic base sufficient to react with one of the enantiomers of the racemic mixture; ii) precipitating from the reaction solution formed in step i) the diastereomeric salt; iii) separating said precipitated diastereomeric salt; iv) decomposing the salt into its enantiomeric component and its organic base component; and v) isolating a substantially pure enantiomer from said decomposed salt.Type: GrantFiled: January 24, 1995Date of Patent: November 12, 1996Assignee: Albemarle CorporationInventors: Deepak R. Patil, Venkataraman Ramachandran
-
Patent number: 5118839Abstract: A process for preparing nitro substituted polyarylketones of the formula: ##STR1## is disclosed. The process involves the condensation of ##STR2## where R.sub.A is hydrogen, --COOH, or C.sup.1 to C.sub.12 linear or branched alkyl, Y and Y' are the same or different and are a chemical bond ##STR3## or --Si(CH.sub.3).sub.2 -- and m is 0 or 1 and X is halo. These nitro groups of these compounds can be reduced to provide the corresponding amines, which are useful for the preparation of thermally stable high melting polyimides.Type: GrantFiled: September 4, 1990Date of Patent: June 2, 1992Assignee: Ethyl CorporationInventors: Allan A. Eisenbraun, Venkataraman Ramachandran
-
Patent number: 5073552Abstract: Substituted benzophenones are disclosed having the following formula ##STR1## where R.sub.A and R.sub.B are each independently COOH, C.sub.1 to C.sub.12 linear or branched alkyl or taken together to form an anhydride ring, R is nitro or amino unsubstituted or substituted with at least one C.sub.1 to C.sub.6 linear or branched alkyl, phenyl or substituted phenyl, the substituents being one or more C.sub.1 to C.sub.6 linear or branched alkyl or C.sub.6 to C.sub.10 aryl, Y and Y' are the same or different and are a chemical bond ##STR2## and m is 0 or 1 with the proviso that both R.sub.A and R.sub.B can not be hydrogen.Processes to produce these benzophenones are also disclosed.Type: GrantFiled: September 4, 1990Date of Patent: December 17, 1991Assignee: Ethyl CorporationInventors: Mark W. Beltz, Venkataraman Ramachandran
-
Patent number: 5061810Abstract: Substituted benzophenones are disclosed having the following formula ##STR1## where R.sub.A and R.sub.B are --OH, C.sub.1 to C.sub.12 linear or branched alkoxy or taken together with the adjacent carbonyl carbons form an anhydride ring, R.sub.1 and R.sub.2 are the same or different and are hydrogen, C.sub.1 to C.sub.6 linear or branched alkyl, halo, aryl unsubstituted or substituted with one or more aryloxy groups or R.sub.1 and R.sub.2 taken together are (CH.sub.2).sub.x where x is an integer from 3 to 6 with the proviso that R.sub.1 and R.sub.2 cannot both be hydrogen.Processes to produce these benzophenones are also disclosed.Type: GrantFiled: November 28, 1989Date of Patent: October 29, 1991Assignee: Ethyl CorporationInventor: Venkataraman Ramachandran
-
Patent number: 4824988Abstract: In a process for preparing a (trifluoromethyl)napthalene by reacting a halonapthalene with a trifluoroacetate in the presence of cuprous iodide and a dipolar aprotic solvent and separating out the inorganic ingredients of the final reaction mixture in the recovery of the product, the cuprous iodide is recovered by washing the separated inorganic ingredients with an alcohol and a carboxylic acid and then with water to purify the cuprous iodide.Type: GrantFiled: October 26, 1987Date of Patent: April 25, 1989Assignee: Ethyl CorporationInventors: Ronny W. Lin, Venkataraman Ramachandran
-
Patent number: 4785131Abstract: 6-Alkoxy-5-halo-1-cyanonaphthalenes, useful as pharmaceutical intermediates, are prepared by (1) reacting a 6-alkoxytetralone with cyanide ion and a Lewis acid in a nitroalkane or nitroarene solvent to form a 6-alkoxy-1-cyano-3,4-dihydronaphthalene, (2) intimately mixing the resultant solution with an aqueous base selected from alkali metal, alkaline earth metal, and tetraalkylammonium hydroxides, alkoxides, carbonates, and bicarbonates to aromatize the 6-alkoxy-1-cyano-3,4-dihydronaphthalene, and (3) halogenating the resultant 6-alkoxy-1-cyanonaphthalene while still in the nitroalkane or nitroarene solvent.Type: GrantFiled: October 26, 1987Date of Patent: November 15, 1988Assignee: Ethyl CorporationInventor: Venkataraman Ramachandran
-
Patent number: 4764635Abstract: A hydroaromatic compound is aromatized by heating it at about 100.degree.-300.degree. C. in the presence of a hydrogen acceptor. In a preferred embodiment of the invention, the hydroaromatic compound is a dihydronaphthalene bearing an electron-withdrawing substitutent, e.g., a cyanodihydronaphthalene.Type: GrantFiled: August 14, 1986Date of Patent: August 16, 1988Assignee: Ethyl CorporationInventors: Venkataraman Ramachandran, David M. Mohr
-
Patent number: 4762943Abstract: A dihydroaromatic compound is aromatized by intimately contacting it with a base selected from alkali metal, alkaline earth metal, and tetraalkylammonium hydroxides, alkoxides, carbonates, and bicarbonates in the presence of a hydrogen acceptor. In a preferred embodiment of the invention, the dihydroaromatic compound is a dihydronaphthalene bearing an electron-withdrawing substituent, e.g., a cyanodihydronaphthalene.Type: GrantFiled: June 30, 1986Date of Patent: August 9, 1988Assignee: Ethyl CorporationInventors: Venkataraman Ramachandran, John R. Maloney
-
Patent number: 4727148Abstract: A 4-cyclohexenylpyridine is brominatively aromatized to the corresponding 4-phenylpyridine by brominating the cyclohexenylpyridine, such as a 4-(halocyclohexenyl)pyridine, especially a 4-(4-halocyclohex-3-enyl)pyridine hydrochloride, and heating the brominated product in the presence or absence of any added base or hydrogen acceptor to form, e.g., a 4-(halophenyl)pyridine. The invention is of particular utility in the manufacture of intermediates of antibacterial 1-alkyl-1,4-dihydro-4-oxo-7-(4-pyridyl)-3-quinolinearcarboxylic acids.Type: GrantFiled: August 25, 1986Date of Patent: February 23, 1988Assignee: Ethyl CorporationInventors: Paul F. Ranken, Venkataraman Ramachandran
-
Patent number: 4649202Abstract: A 4-cyclohexenylpyridine is brominatively aromatized to the corresponding 4-phenylpyridine by brominating the cyclohexenylpyridine, such as a 4-(halocyclohexenyl)pyridine, especially a 4-(4-halocyclohex-3-enyl)pyridine hydrochloride, and heating the brominated product in the presence or absence of any added base or hydrogen acceptor to form, e.g., a 4-(halophenyl)pyridine. The invention is of particular utility in the manufacture of intermediates of antibacterial 1-alkyl-1,4-dihydro-4-oxo-7-(4-pyridyl)-3-quinolinecarboxylic acids.Type: GrantFiled: March 22, 1985Date of Patent: March 10, 1987Assignee: Ethyl CorporationInventors: Paul F. Ranken, Venkataraman Ramachandran
-
Patent number: 4604467Abstract: A 4-cyclohexenylpyridine is brominatively aromatized to the corresponding 4-phenylpyridine by brominating the cyclohexenylpyridine, such as a 4-(halocyclohexenyl)pyridine, especially a 4-(4-halocyclohex-3-enyl)pyridine hydrohalide, and heating the brominated product in an inert solvent and in the presence of a base to form, e.g., a 4-(halophenyl)pyridine. The invention is of particular utility in the manufacture of intermediates of antibacterial 1-alkyl- 1,4-dihydro-4-oxo-7-(4-pyridyl)-3-quinolinecarboxylic acids.Type: GrantFiled: March 25, 1985Date of Patent: August 5, 1986Assignee: Ethyl CorporationInventors: Venkataraman Ramachandran, Paul F. Ranken
-
Patent number: 4590012Abstract: An alpha-arylacrylonitrile is prepared by reacting an aryl ketone having a removable hydrogen alpha to the carbonyl group with an alkali metal cyanide and a Lewis acid other than aluminum chloride, preferably in the presence of a solvent. In a preferred embodiment, the aryl ketone is a tetralone, the cyanide is sodium cyanide, the Lewis acid is boron trifluoride, and the product is a 1-cyano-3,4-dihydronaphthalene.Type: GrantFiled: May 17, 1985Date of Patent: May 20, 1986Assignee: Ethyl CorporationInventor: Venkataraman Ramachandran
-
Patent number: 4590013Abstract: An alpha-arylacrylonitrile is prepared by reacting an aryl ketone having a removable hydrogen alpha to the carbonyl group with a cyanide ion source which is free of radicals that would stabilize a cyanohydrin corresponding to the aryl ketone and with a Lewis acid, preferably in the presence of a solvent. In a preferred embodiment, the aryl ketone is a tetralone, the cyanide ion source is hydrogen cyanide, the Lewis acid is aluminum chloride, and the product is a 1-cyano-3,4-dihydronaphthalene.Type: GrantFiled: May 17, 1985Date of Patent: May 20, 1986Assignee: Ethyl CorporationInventors: John R. Maloney, Venkataraman Ramachandran
-
Patent number: 4590010Abstract: 6-Alkoxy-5-trifluoromethyl-1-naphthoic acids are prepared by (1) cyanating a 6-alkoxytetralone so as to form a 6-alkoxy-1-cyano-3,4-dihydronaphthalene, (2) converting the 6-alkoxy-1-cyano-3,4-dihydronaphthalene to a naphthoic acid precursor selected from a 6-alkoxy-1-cyanonaphthalene and a hydrocarbyl 6-alkoxy-1-naphthoate, (3) halogenating the naphthoic acid precursor to the corresponding 5-halo derivative, (4) trifluoromethylating the 5-halo derivative to replace the 5-halo substituent with a 5-trifluoromethyl group, and (5) hydrolyzing the resultant product to a 6-alkoxy-5-trifluoromethyl-1-naphthoic acid. In a preferred embodiment of the invention, the process is conducted so as to prepare 6-methoxy-5-trifluoromethyl-1-naphthoic acid, which, like the other products, is known to be useful as a pharmaceutical intermediate.Type: GrantFiled: April 18, 1985Date of Patent: May 20, 1986Assignee: Ethyl CorporationInventors: Venkataraman Ramachandran, Robert I. Davidson, John R. Maloney
-
Patent number: 4552963Abstract: The yield of Diels-Alder product obtained by reacting a haloprene with a 4-vinylpyridine is increased by conducting the reaction in the presence of a boron trifluoride catalyst, preferably a boron trifluoride etherate. The product obtained by the reaction, a mixture of 4-(chlorocyclohex-3-enyl)pyridines, is useful in the production of antibacterial 1-alkyl-1,4-dihydro-4-oxo-7-pyridinyl-3-quinolinecarboxylic acids.Type: GrantFiled: May 23, 1983Date of Patent: November 12, 1985Assignee: Ethyl CorporationInventor: Venkataraman Ramachandran
-
Patent number: 4552964Abstract: A 4-(1-chlorovinyl)pyridine, preferably 4-(1-chlorovinyl)pyridine itself, is reacted with a butadiene, preferably chloroprene, to prepare a 4-(1-chlorocyclohex-3-enyl)pyridine. The preferred products are useful as intermediates in the preparation of antibacterial 1-alkyl-1,4-dihydro-4-oxo-7-pyridinyl-3-quinolinecarboxylic acids.Type: GrantFiled: September 16, 1983Date of Patent: November 12, 1985Assignee: Ethyl CorporationInventor: Venkataraman Ramachandran