Patents by Inventor Heinz Litterer
Heinz Litterer 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: 5744010Abstract: The invention relates to a process for the preparation of acesulfam salts by reaction of salts of amidosulfonic acid with diketene to give a salt of acetoacetamidosulfonic acid (I), ring closure by the action of at least about an equivalent amount of SO.sub.3, at least this ring closure reaction being carried out in the presence of a halogenated, aliphatic hydrocarbon as an inert solvent, treatment of the cyclization product with water and conversion of the resulting acesulfam-H (II) into the form of a non-toxic salt, which comprises, in the work-up by distillation of the resulting crude solvent, after removal of water and low-boilers and recovery of solvent sufficiently pure for reuse in the preparation of compounds (I) and/or (II), directly returning :he remaining, solvent-containing distillation residue, without further purification, into the system downstream of the reaction vessel for carrying out the ring closure reaction.Type: GrantFiled: June 19, 1995Date of Patent: April 28, 1998Assignee: Hoechst AktiengesellschaftInventors: Gunter Roscher, Heinz Litterer, Axel Engelmann, Wolf-Dietmar Kaufmann, Bernd Laugwitz, Hans-Dietmar Schnabel
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Patent number: 5264094Abstract: Process for the preparation of fluorobenzenes having at least one hydrogen atom as ring substituent and, optionally, further substituents, which, independently of each other, can be chlorine, bromine, nitro, hydroxyl, C.sub.1 -C.sub.3 -alkoxy or C.sub.1 -C.sub.3 -alkyl, the number of nitro groups being not more than 2 and the number of hydroxyl groups and alkoxy groups being not more than 3 in each case, by heating the corresponding benzaldehydes, substituted by at least one flourine atom, in the presence of a catalyst, characterized in that the reaction product is immediately removed from the reaction zone.Type: GrantFiled: April 24, 1992Date of Patent: November 23, 1993Assignee: Hoechst AktiengesellschaftInventors: Frank P. Sistig, Ernst I. Leupold, Heinz Litterer
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Patent number: 5100520Abstract: Selectively dehalogenated thiophene derivatives are obtained from compounds of the formula II ##STR1## by an electrochemical reaction in a divided electrolysis cell in the presence of a suitable solvent, an onium compound or a compound which is converted into an onium compound in the electrolyte, and a conducting salt. Thiophene derivatives are important intermediates in the production of pharmaceuticals and plant protection agents.Type: GrantFiled: February 2, 1990Date of Patent: March 31, 1992Assignee: Hoechst AktiengesellschaftInventors: Steffen Dapperheld, Michael Feldhues, Heinz Litterer, Frank P. Sistig, Peter Wegener
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Patent number: 4937395Abstract: A process for the preparation of fluorobenzenes of the formula I ##STR1## wherein R.sup.1, R.sup.2 and R.sup.3 are equal or different and represent H, F, Cl or alkyl having from 1 to 3 carbon atoms, at least one of these radicals being fluorine, and S.sup.1 and S.sup.2 being equal or different and represent H or a group reducing the electron density at the benzene nucleus, which comprises subjecting a compound of the formula II ##STR2## in which R.sup.1, R.sup.2, R.sup.3, S.sup.1 and S.sup.2 have the aforementioned meaning to a decarbonylation at a zeolite catalyst.Type: GrantFiled: July 14, 1989Date of Patent: June 26, 1990Assignee: Hoechst AktiengesellschaftInventors: Heinz Litterer, Hans J. Metz, Theodor Papenfuhs, Frank P. Sistig, Ernst I. Leupold
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Patent number: 4931568Abstract: Thiophene ethers having relatively large side chains can be easily obtained by reacting 2-, 3-, 2,3-, 2,4- or 3,4-C.sub.1 -C.sub.3 -alkoxythiophenes in the presence of an acid catalyst with a compound containing an OH group. The novel thiophene ethers are suitable as monomers for electrically conducting polymers.Type: GrantFiled: February 9, 1989Date of Patent: June 5, 1990Assignee: Hoechst AktiengesellschaftInventors: Peter Wegener, Michael Feldhues, Heinz Litterer
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Patent number: 4650915Abstract: The invention relates to a process for preparing p-chlorotoluene and/or m-chlorotoluene by ring-chlorination of toluene by using the following two pages (a) and (b) when further processing the toluene chlorination product composed of mixed isomers:(a) Isolation of p-chlorotoluene from a mixture of o-, m- and p-chlorotoluene by selective adsorption of p-chlorotoluene onto a mesoporous or macroporous zeolite and subsequent desorption of p-chlorotoluene(b) Treatment of an o-chlorotoluene-rich mixture of isomers with an isomerization catalyst.For the exclusive preparation of p-chlorotoluene first p-chlorotoluene is isolated and removed from the toluene chlorination product in stage (a). The remaining mixed isomers are then treated in stage (b) to increase their content of m- and p-isomers and then returned into stage (a).Type: GrantFiled: August 9, 1985Date of Patent: March 17, 1987Assignee: Hoechst AktiengesellschaftInventors: Hans-Jurgen Arpe, Heinz Litterer, Norbert Mayer
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Patent number: 4605809Abstract: The present invention relates to aluminosilicates and silica gels having a low content of transition elements, to a process for their manufacture and to their use as a catalysts or catalyst supports. Said aluminosilicates or silica gels are prepared by treating them with a solution of complexing agents at a temperature of from 70.degree. to 150.degree. C. The manufacture of low-molecular-weight olefins from methanol is one possible application field of said aluminosilicates, used as a catalyst.Type: GrantFiled: October 27, 1983Date of Patent: August 12, 1986Assignee: Hoechst AktiengesellschaftInventors: Heinz Litterer, Friedrich Wunder, Ernst I. Leupold, Herbert Baltes
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Patent number: 4554380Abstract: The invention provides a process for the manufacture of o-toluidine and/or m-toluidine and/or p-toluidine, which comprises the two following steps (a) and (b):(a) treatment of a toluidine isomer mixture or of the not intended toluidine isomer or of one of the not intended toluidine isomers with an isomerization catalyst selected from the group of synthetic zeolites of the pentasil type,(b) isolation of the intended isomer or one of the intended isomers from the isomer mixture formed in step (a) by selective adsorption to a medium-pore or large-pore zeolite and subsequent desorption, furthermore discharge of the isolated isomer and recycling of the remaining isomer mixture to step (a).Type: GrantFiled: August 27, 1984Date of Patent: November 19, 1985Assignee: Hoechst AktiengesellschaftInventors: Hans-Jurgen Arpe, Heinz Litterer
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Patent number: 4522800Abstract: A method for making crystalline aluminosilicate ZSM-34 zeolites, useful as catalysts for making C.sub.2 -C.sub.4 -olefins from methanol, from a reaction mixture containing silicon, aluminum, sodium, potassium, and an organic template compound which is (i) a salt of an ammonium compound of di-, tri-, or tetra-ethanolamine or (ii) a mixture of at least one of diethanolamine and triethanolamine with certain lower alkanols, lower alkylene diols, or lower alkyl iodides, sulfates, or p-toluenesulfonates.Type: GrantFiled: May 5, 1983Date of Patent: June 11, 1985Assignee: Hoechst AktiengesellschaftInventors: Herbert Baltes, Heinz Litterer, Ernst I. Leupold, Friedrich Wunder
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Patent number: 4487971Abstract: The invention provides a process for the isolation of crystalline 1,3-cyclohexanedione from the crude product formed in the catalytic gaseous phase cyclization of 5-oxohexanoic acid. Before or directly after condensation an auxiliary component consisting of at least one compound selected from the group consisting of cyclic hydrocarbons, chlorinated aliphatic hydrocarbons and monoethers is added to the crude product, subsequently the mixture of crude product and auxiliary component is distilled under normal or reduced pressure until the reaction water is removed and the residual content of auxiliary component in the remaining concentrate has attained a defined value, and the precipitated crystalline 1,3-cyclohexanedione is filtered off. Alternatively, the auxiliary component added may be distilled off substantially completely.Type: GrantFiled: September 30, 1983Date of Patent: December 11, 1984Assignee: Hoechst AktiengesellschaftInventors: Heinz Litterer, Helmut Meidert
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Patent number: 4481376Abstract: A method for the catalytic conversion of methanol and/or dimethyl ether to lower olefins with an aluminosilicate zeolite catalyst containing zirconium and/or hafnium together with manganese.Type: GrantFiled: February 9, 1983Date of Patent: November 6, 1984Assignee: Hoechst AktiengesellschaftInventors: Friedrich Wunder, Ernst I. Leupold, Heinz Litterer
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Patent number: 4480128Abstract: The invention provides a process for the manufacture of o-toluidine and/or m-toluidine and/or p-toluidine, which comprises the two following steps (a) and (b):(a) treatment of a toluidine isomer mixture or of the not intended toluidine isomer or of one of the not intended toluidine isomers with an isomerization catalyst selected from the group of synthetic zeolites of the pentasil type,(b) isolation of the intended isomer or one of the intended isomers from the isomer mixture formed in step (a) by selective adsorption to a medium-pore or large-pore zeolite and subsequent desorption, furthermore discharge of the isolated isomer and recycling of the remaining isomer mixture to step (a).Type: GrantFiled: April 12, 1983Date of Patent: October 30, 1984Assignee: Hoechst AktiengesellschaftInventors: Hans-J/u/ rgen Arpe, Heinz Litterer