Process Of Forming Partially Hydrogenated Pyridine Ring Patents (Class 546/249)
  • Patent number: 5530134
    Abstract: A process for the synthesis of compounds of the formulas Ia and Ib below, wherein R.sub.1, R.sub.2, and R.sub.3, which are the same or different, are each selected from hydrogen and C.sub.1 -C.sub.4 alkyl, including the compound Anabaseine (Ia, wherein R.sub.1 =R.sub.2 R.sub.3 =H) (3,4,5,6-tetrahydro-2', 3'-bipyridine), the process comprising reacting sodium salt of .delta.-valerolactone with substituted ethyl nicotinate derivative to produce the Claisen product sodium 3-nicotinoyl-2-tetrahydropyranone enolate derivative, heating the sodium 3-nicotinoyl-2-tetrahydropyranone enolate derivative with concentrated HCl to produce 3-(5-chloro-1-pentanone-1-yl) pyridine derivative, dissolving the 3-(5-chloro-1-pentanone-1-yl) pyridine derivative in ethanol and then heating the 3-(5-chloro-1-pentanone-1-yl) pyridine derivative in ethanol with ethanolic ammonia solution in a sealed container to produce the compound Ia.
    Type: Grant
    Filed: September 6, 1994
    Date of Patent: June 25, 1996
    Assignee: Synphar Laboratories Inc.
    Inventors: Mohsen Daneshtalab, Dai Nguyen, Inderjit Sidhu, Ronald G. Micetich
  • Patent number: 5502050
    Abstract: Inhibitor of the use of tetrahydrobiopterin as a cofactor for nitric oxide synthase, e.g., substituted 4-phenyl(hydropyridines) such as 1-methyl-4-(3',4'-dihydroxyphenyl)-1,2,3,6-tetrahydropyridine or, 4-(3',4'-dihydroxyphenyl)-1,2,3,6-tetrahydropyridine) or tetrahydropterin analog which does not replace tetrahydrobiopterin as a substrate for nitric oxide synthase such as (6R,S)-6,7-dimethyl-tetrahydropterin or (6R,S)-tetrahydrofolic acid or 2,4-diamino-, 2,6-diamino, or 4,6-diamino mono- or disubstituted pyrimidines or the corresponding pyrimidine-3-oxides such as 2,4-diamino-6-(diethylamino)pyrimidine, 2,4-diamino-6-piperidino-pyrimidine-3-oxide, 2,4-diamino-6-hydroxypyrimidine, 4,6-diamino-2-hydroxypyrimidine or 2,5-diamino-4,6-dihydroxypyrimidine is administered to inhibit nitric oxide synthesis from arginine in vascular cells in a subject in need of such inhibition (e.g., for prophylaxis or treatment of cytokine- or endotoxin-induced hypotension (e.g., septic shock).
    Type: Grant
    Filed: November 29, 1993
    Date of Patent: March 26, 1996
    Assignee: Cornell Research Foundation, Inc.
    Inventor: Steven S. Gross
  • Patent number: 5442070
    Abstract: This invention relates to new derivatives of fluoro quinoline carboxylic-3 acid having general formula (I), ##STR1## wherein R is a hydrogen atom or an alkyl radical and Hal is a halogen atom, as well as salts thereof, when they exist, preparation thereof and utilization as synthesis intermediary.
    Type: Grant
    Filed: April 7, 1994
    Date of Patent: August 15, 1995
    Assignee: Laboratoire Roger Bellon
    Inventors: Christophe Daubie, Jean-Jacques Legrand, Clive Pemberton
  • Patent number: 5434266
    Abstract: Broad spectrum glycosidase inhibitors are produced from monosaccharide lactams by conversion to amidines, amidrazones, or amidoximes. The inhibitors have the general formula: ##STR1## wherein the N and C are joined as part of a monosaccharide azaanalog ring and wherein --NRQ, together with the nitrogen and carbon atoms, form a chemical group selected from amidines, amidrazones, and amidoximes.
    Type: Grant
    Filed: April 29, 1993
    Date of Patent: July 18, 1995
    Assignee: Cornell Research Foundation, Inc.
    Inventors: Bruce Ganem, Michael K. Tong, George Papandreou
  • Patent number: 5286867
    Abstract: 1-Sulfonyloxy-2-pyridones of the formula I ##STR1## show good radiation sensitivity over a wide spectral range and are therefore valuable as photoactive compounds in radiation-sensitive mixtures.
    Type: Grant
    Filed: April 20, 1992
    Date of Patent: February 15, 1994
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Gerhard Lohaus, Walter Spiess, Georg Pawlowski
  • Patent number: 5231185
    Abstract: Broad spectrum glycosidase inhibitors are produced from monosaccharide lactams by conversion to amidines, amidrazones, or amidoximes. The inhibitors have the general formula: ##STR1## wherein the N and C are joined as part of a monosaccharide azaanalog ring and wherein --NRQ, together with the nitrogen and carbon atoms, form a chemical group selected from amidines, amidrazones, and amidoximes.
    Type: Grant
    Filed: July 23, 1991
    Date of Patent: July 27, 1993
    Assignee: Cornell Research Foundation, Inc.
    Inventors: Bruce Ganem, Michael K. Tong, George Papandreou
  • Patent number: 5206369
    Abstract: An improved process for dehydrating dialkyl 2,6-bis(trifluoromethyl)-2,6-dihydroxy-4-(alkyl)-3,5-piperidinedicarboxyla tes using concentrated sulfuric acid essentially in the absence of a solvent to prepare the corresponding dialkyl 2,6-bis(trifluoromethyl)dihydro-4-(alkyl)-3,5-pyridinedicarboxylates.
    Type: Grant
    Filed: January 21, 1992
    Date of Patent: April 27, 1993
    Assignee: Monsanto Company
    Inventor: William H. Miller
  • Patent number: 5126457
    Abstract: The invention is directed to processes for the preparation of dimethyl-1,4-dihydro-2,6-dimethyl-4-(2'-nitrophenyl)-pyridine-3,5-dicarbox ylate by reacting 1-methoxy-1-(2'-nitrophenyl)-N-(2'-nitrophenyl)methylene methanamie or 1-(2'-nitrophenyl)-N,N'-bis-(2'-nitrophenyl) methylene methanediamine with methyl acetoacetate in the presence of an amine compound or by reacting the monomeric or trimeric from of 2-nitrobenzaldimine with methyl acetoacetate.
    Type: Grant
    Filed: March 8, 1989
    Date of Patent: June 30, 1992
    Assignee: Egis Gyogyszergyar
    Inventors: Pal Benko, Daniel Bozsing, Laszlo Levai, Gyorgyi Kovanyi nee Lax, Gyorgy Mikite, Peter Tompe, Eva Furdyga, Ilona Dinnyes nee Nagy, Eva Poczik, Gyorgyi Zalavari nee Dosa, Ivan Beck, Istvan Simonyi, Kalman Nagy, Janos Imre, Erzsebet Kiss nee Bertok, Eva J. Tajthy nee Juhasz, Attila Mandi, Frigyes Gorgenyi
  • Patent number: 5104880
    Abstract: An acetylcholinesterase inhibitor is provided of the general formula (I): ##STR1## wherein R.sub.1 is H, (C.sub.1 -C.sub.8)alkyl or halo; R.sub.2 is H or (C.sub.1 -C.sub.8)alkyl; R.sub.3 and R.sub.4 are individually H, (C.sub.1 -C.sub.8)alkyl, NO.sub.2, hydroxy or halo; R.sub.5 and R.sub.6 are individually H, (C.sub.1 -C.sub.8)akyl, aryl or aralkyl; R.sub.7 is H, halo or (C.sub.1 -C.sub.8)alkyl, R.sub.8 is halo or (C.sub.1 -C.sub.8)alkyl; R.sub.9 is absent or is H; and the bonds represented by--are individually absent or, together with the adjacent bond, form the unit C.dbd.C, with the proviso that if both of the bonds represented by--are present, R.sub.3 and R.sub.4 cannot both be H unless R.sub.7 or R.sub.8 is halo; and the pharmaceutically acceptable salts thereof.
    Type: Grant
    Filed: May 1, 1991
    Date of Patent: April 14, 1992
    Assignee: Mayo Foundation for Medical Education and Research
    Inventor: Alan P. Kozikowski
  • Patent number: 4958024
    Abstract: A process for preparing a 2-carbamoylocxyalkyl-1,4-dihydropyridine derivative represented by the general formula: ##STR1## which comprises: (a) reacting a 3-amino-3-carbamoyloxyalkylacrylic acid derivative represented by the general formula: ##STR2## with a benzylidene compound represented by the general formula: ##STR3## (b) reacting the 3-amino-3-carbamoyloxyalkylacrylic acid derivative of the general formula II with an aldehyde compound represented by the general formula: ##STR4## and a .beta.-keto-ester compound represented by the general formula:R.sup.4 --CO--CH.sub.2 --COOR.sup.2 (V)(c) reacting a 3-carbamoyloxyalkylpropiolic acid derivative represented by the general formula: ##STR5## with the benzylidene compound of the general formula III and ammonia or its salt; or(d) reacting the 3-carbamoyloxyalkylpropiolic acid derivative of the general formula VI with the aldehyde compound of the general formula IV, the .beta.-keto-ester compound of the general formula V and ammonia or its salt.
    Type: Grant
    Filed: August 10, 1988
    Date of Patent: September 18, 1990
    Assignee: Banyu Pharmaceutical Company, Ltd.
    Inventors: Tetsuji Miyano, Kunio Suzuki, Ryosuke Ushijima, Susumu Nakagawa
  • Patent number: 4929731
    Abstract: The present invention relates to a method for the synthesis of certain bridged fused ring pyridines. Such bridged fused ring pyridines can be converted to huperzine A and analogs of huperzine A. The present invention also covers such bridged fused ring pyridines, compounds utilized for the preparation of the bridged fused ring pyridines and analogs of huperzine A.
    Type: Grant
    Filed: February 21, 1989
    Date of Patent: May 29, 1990
    Assignee: University of Pittsburgh
    Inventors: Alan P. Kozikowski, Yan Xia
  • Patent number: 4908398
    Abstract: Poly-dihydro-2,6-dimethylpyridine-3,5-dicarboxylesters of general formula (I) ##STR1## in which A, B, m, n, k, j, R, R.sup.1 and R.sup.2 have the meanings defined in the text, useful as thermal stabilizers for synthetic polymers, in particular for polyvinylchloride-based masses.The compounds of formula (I) are preferably used in combination with the usual stabilizers based on organic metal derivatives. They can also be used combined with agents which exert a synergic action in maintaining a low color of manufactured articles subjected to heating, and in particular with betadicarbonyl compounds of formula (II):R.sup.3 --CO--CH.sub.2 --CO--R.sup.4 (II)in which R.sup.3 and R.sup.4 have the meanings defined in the text, in masses containing organic calcium and zinc salts as basic stabilizers.
    Type: Grant
    Filed: March 29, 1988
    Date of Patent: March 13, 1990
    Assignee: Lagor S.p.A.
    Inventors: Giuseppe Li Bassi, Roberto Ortica
  • Patent number: 4857475
    Abstract: Labellable reagents for fluormetric assays comprise a cyclic condensation product of a .beta.-diketone, an aldehyde and an NH.sub.2 -bearing macromolecule, for example an antigen or antibody or a substance having an active group to which an antibody or antigen is linked. The reagents can chelate lanthanide metal ions such as Eu(II) and Tb(III) to form fluorescing complexes which can be used as labelled reagents for fluorometric assay of organic substances, for example antigens, antibodies and other substances occurring in body fluids.
    Type: Grant
    Filed: April 17, 1986
    Date of Patent: August 15, 1989
    Assignee: Roger Philip Ekins
    Inventor: Salifu Dakubu
  • Patent number: 4795814
    Abstract: Process for preparing dihydropyridine derivatives and salts and esters thereof represented by the general formula ##STR1## from a phenyl derivative and an enamine derivative in which the phenyl derivative is prepared by reacting a compound of the formula ##STR2## with a compound of the formula ##STR3## in the presence of an aromatic amine selected from o-, m-, p- anisidine; m-, p-toluidine; p-chloroaniline; aniline and o-phenetidine.
    Type: Grant
    Filed: December 18, 1986
    Date of Patent: January 3, 1989
    Assignee: Otsuka Pharmaceutical Co., Ltd.
    Inventors: Shinji Nishitani, Junichi Minamikawa, Masanobu Kano, Junichiro Otsubo, Yoshiaki Manabe
  • Patent number: 4780538
    Abstract: A process for the preparation of 1,4-dihydropyridine compounds, especially N-substituted 1,4-dihydropyridine compounds, is disclosed. The compounds are useful as cardiovascular agents and also as starting materials for the preparation of certain cyclized compounds which have properties as calcium entry blockers.
    Type: Grant
    Filed: February 12, 1986
    Date of Patent: October 25, 1988
    Assignee: Merck & Co., Inc.
    Inventors: Steven M. Pitzenberger, Barry M. Trost
  • Patent number: 4757147
    Abstract: This invention relates to novel highly branched amines and to a process of preparing same which comprises:(1) the preparation of a vinylimine from branched aldehydes and ammonia;(2) the dimerization and intermolecular condensation of such vinylimines to cyclic diamines; and(3) hydrolysis of such cyclic diamines to other diamines.
    Type: Grant
    Filed: September 5, 1985
    Date of Patent: July 12, 1988
    Assignee: Petrolite Corporation
    Inventors: Benjamin T. Outlaw, Bernardus A. Oude Alink
  • Patent number: 4703119
    Type: Grant
    Filed: June 4, 1985
    Date of Patent: October 27, 1987
    Assignee: Bayer Aktiengesellschaft
    Inventors: Egbert Wehinger, Horst Meyer
  • Patent number: 4600778
    Abstract: In the preparation of a 1,4-dihydropyridine of the formula ##STR1## in which R is a phenyl radical which is optionally substituted once or twice by nitro and/or chlorine,R.sub.1 is a C.sub.1 -C.sub.4 -alkyl radical which is optionally substituted by a C.sub.1 -C.sub.4 -alkoxy group, andR.sub.2 is a C.sub.1 -C.sub.12 -alkyl radical which is optionally substituted by a C.sub.1 -C.sub.4 -alkoxy group, a trifluoromethyl group or the radical (C.sub.6 H.sub.5 CH.sub.2) (CH.sub.3)N,by preparing an ylidene compound of the formula ##STR2## and reacting such ylidene compound with an enamine compound of the formula ##STR3## the improvement which comprises preparing the ylidene compound by reaction of a ketocarboxylic ester of the formula ##STR4## with an aldehyde of the formula RCHO, in a solvent in the presence of a catalytic amount of any acetate salt of an amine, at a temperature from about -10.degree. C. up to 100.degree. C. The products symmetrical or unsymmetrical, are produced in high yield and purity.
    Type: Grant
    Filed: March 20, 1984
    Date of Patent: July 15, 1986
    Assignee: Bayer Aktiengesellschaft
    Inventors: Werner Teller, Wolfgang Koebernick, Arthur Haaf, Paul Naab, Michael Preiss
  • Patent number: 4469871
    Abstract: One aspect of the invention resides in the three step process for preparing cardiotonically active 1,2-dihydro-6-(lower-alkyl)-2-oxo-5-(pyridinyl)nicotinonitriles or 1,2-dihydro-6-(lower-alkyl)-2-oxo-5-(pyridinyl)nicotinamides which comprises reacting a pyridinylmethyl lower-alkyl ketone with tri-(lower-alkyl) orthoformate, acetic anhydride and acetic acid to produce 2-(lower-alkoxy)-1-(pyridinyl)ethenyl lower-alkyl ketone reacting the latter with cyanoacetamide or malonamide in the presence of a basic condensing agent and neutralizing the reaction mixture, where pyridinyl is 4- or 3-pyridinyl or 4- or 3-pyridinyl having one or two lower-alkyl substituents. Other aspects of the invention reside in the intermediate 2-(lower-alkoxy)-1-(pyridinyl)ethenyl lower-alkyl ketones, their salts and their two step conversion, as described above, to 1,2-dihydro-6-(lower-alkyl)-2-oxo-5-(pyridinyl)-nicotinonitriles or corresponding nicotinamides.
    Type: Grant
    Filed: March 3, 1983
    Date of Patent: September 4, 1984
    Assignee: Sterling Drug Inc.
    Inventor: Karl O. Gelotte
  • Patent number: 4417054
    Abstract: One aspect of the invention resides in the three step process for preparing cardiotonically active 1,2-dihydro-6-(lower-alkyl)-2-oxo-5-(pyridinyl)nicotinonitriles (III, Q is CN) or 1,2-dihydro-6-(lower-alkyl)-2-oxo-5-(pyridinyl)nicotinamides (III, Q is CONH.sub.2) which comprises reacting a pyridinylmethyl lower-alkyl ketone (I) with tri-(lower-alkyl) orthoformate, acetic anhydride and acetic acid to produce 2-(lower-alkoxy)-1-(pyridinyl)ethenyl lower-alkyl ketone (II), reacting II with cyanoacetamide or malonamide in the presence of a basic condensing agent and neutralizing the reaction mixture, where pyridinyl is 4- or 3-pyridinyl or 4- or 3-pyridinyl having one or two lower-alkyl substituents. Other aspects of the invention resides in the intermediate 2-(lower-alkoxy)-1-(pyridinyl)ethenyl lower-alkyl ketones (II) and its two step conversion, as described above, to said compounds (III, Q is CN or CONH.sub.2).
    Type: Grant
    Filed: May 24, 1982
    Date of Patent: November 22, 1983
    Assignee: Sterling Drug Inc.
    Inventor: Karl O. Gelotte
  • Patent number: 4413127
    Abstract: The invention resides in a process for preparing cardiotonically active 1,2-dihydro-6-(lower-alkyl)-2-oxo-5-(pyridinyl)nicotinonitriles (III) which comprises reacting a pyridinylmethyl lower-alkyl ketone (I) with tri-(lower-alkyl) orthoformate, acetic anhydride and acetic acid to produce 2-(lower-alkoxy)-1-(pyridinyl)ethenyl lower-alkyl ketone (II) and then reacting II with malononitrile in a lower-alkanol, where pyridinyl is 4- or 3-pyridinyl or 4- or 3-pyridinyl having one or two lower-alkyl substituents.
    Type: Grant
    Filed: May 24, 1982
    Date of Patent: November 1, 1983
    Assignee: Sterling Drug Inc.
    Inventor: Baldev Singh
  • Patent number: 4387230
    Abstract: Dihydropyridines of formula ##STR1## where R.sup.6 is lower alkyl and R.sup.5 is lower alkyl or aryl (lower)alkyl are prepared by a novel process from sodium or potassium salts of 1-substituted-1,6-dihydro-5-hydroxy-3[2H]-pyridones. The dihydropyridines are useful as intermediates for pharmacologically active 1-optionally substituted-3-phenyl or substituted phenylpiperidin-5-ols and esters. Some of the piperidinols and esters are novel; those where the 1-substituent is aryl(lower)alkyl are intermediates, those where the 1-substituent is cycloalkyl(lower)alkyl are analgesics or antidepressants and those in which the 1-position is unsubstituted are anti-secretory agents.
    Type: Grant
    Filed: August 20, 1981
    Date of Patent: June 7, 1983
    Assignee: John Wyeth and Brother Limited
    Inventors: Alan C. White, Robin G. Shepherd
  • Patent number: 4386207
    Abstract: An improved process for the preparation of pyridines and/or hydrogened pyridines that have been substituted with a hydrocarbon group at one or more carbon atoms. .gamma.-cyanoketone, in a gaseous phase and in the presence of hydrogen, is passed over a first catalyst in a reaction zone to form a reaction mixture containing substituted pyridines and/or hydrogenated pyridines and hydrogen. A hydrogen-containing gas is separated from the reaction mixture and, prior to being recycled, is subjected to a two-step catalytic treatment. In the first catalytic treatment step, the hydrogen-containing gas is passed over an iron, nickel, cobalt, or platinum-containing catalyst at a temperature of between about 250.degree. and 550.degree. C. In the second catalytic treatment step, the hydrogen-containing gas is passed over an iron, nickel, or cobalt catalyst at a temperature of between about 550.degree. and 800.degree. C.
    Type: Grant
    Filed: November 13, 1981
    Date of Patent: May 31, 1983
    Assignee: Stamicarbon B.V.
    Inventors: Theodorus F. M. de Graaf, Charles H. Geersheuvels
  • Patent number: 4347363
    Abstract: A process for preparing cardiotonically active 1,2-dihydro-6-methyl-2-oxo-5-(pyridinyl)nicotinonitriles which comprises reacting a pyridinylmethyl methyl ketone with ethoxymethylenemalononitrile, where pyridinyl is 4- or 3-pyridinyl or 4- or 3-pyridinyl having one or two lower-alkyl substituents.
    Type: Grant
    Filed: September 17, 1981
    Date of Patent: August 31, 1982
    Assignee: Sterling Drug Inc.
    Inventor: Baldev Singh
  • Patent number: 4276419
    Abstract: An improved process for the preparation of pyridines and/or hydrogenated pyridines that have been substituted with a hydrocarbon group at one or more carbon atoms, .gamma.-cyanoketone, in a gaseous phase and in the presence of hydrogen, is passed in a reaction zone over a first catalyst containing a catalytically active metal or compound of a metal selected from the group copper, silver, gold, iron, nickel, cobalt, ruthenium, rhodium, palladium, osmium, iridium and platinum to form a reaction mixture. A hydrogen-containing gas is separated from the reaction mixture, passed over a second catalyst containing a catalytically active metal or compound of a metal selected from the group iron, nickel and cobalt at a temperature of between 300.degree. and 800.degree. C., and the hydrogen-containing gas so treated is recycled to the reaction zone.
    Type: Grant
    Filed: September 19, 1979
    Date of Patent: June 30, 1981
    Assignee: Stamicarbon, B.V.
    Inventors: Egidius J. M. Verheijen, Charles H. Geersheuvels
  • Patent number: 4264609
    Abstract: Amrinone intermediates are prepared by reacting 4-picoline with at least three mole equivalents of phosgene per mole of 4-picoline and excess dimethylformamide to produce N-[3-dimethylamino-2-(4-pyridinyl)-2-propenylidene]-N-methylmethaniminium chloride hydrochloride, then reacting the latter with Q-CH.sub.2 CONH.sub.2 and at least three mole equivalents of base in anhydrous medium and then neutralizing the reaction mixture to produce 5-Q-[3,4'-bipyridin]-6(1H)-one, where Q is cyano or carbamyl. Other aspects of the invention are the separate steps of preparing said iminium salt and then converting it to said 5-Q-[3,4'-bipyridin]-6(1H)-one, and also cardiotonic composition and method for increasing cardiac contractility using said iminium salt or pharmaceutically-acceptable acid-addition salt thereof as the active cardiotonic.
    Type: Grant
    Filed: February 26, 1980
    Date of Patent: April 28, 1981
    Assignee: Sterling Drug Inc.
    Inventors: Karl O. Gelotte, Chester J. Opalka, Jr.
  • Patent number: 4234484
    Abstract: Special cyclic enamides are prepared by splitting off alcohols catalytically from the corresponding alkoxylated cyclic amides, in the presence of at least one tetraalkylammonium and/or alkali metal salt of tetrafluoroboric acid and/or of hexafluorophosphoric acid as the catalyst, at a temperature of from about 120.degree. to 250.degree. C., distilling off the detached alcohol and isolating the formed enamide in known manner. Particularly preferred starting compounds are those cyclic amides which have been obtained by anodic alkoxylation of corresponding cyclic N-compounds in an alcohol in the presence of supporting electrolytes which are identical with the catalysts subsequently used for splitting off the alcohol, and by distilling off the alcohol from the reaction batch. The enamides are valuable starting products and intermediates for various syntheses, for example, syntheses of prostaglandins and of other pharmaceuticals.
    Type: Grant
    Filed: April 25, 1978
    Date of Patent: November 18, 1980
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Michael Mitzlaff, Klaus Warning
  • Patent number: 4205174
    Abstract: Process for the production of 6-substituted-4-methyl-2-pyridones having the formula: ##STR1## wherein R is a branched or unbranched alkyl group, a halogenated branched or unbranched alkyl group or a substituted or unsubstituted aryl group. Senecioic acid amide having the formula: ##STR2## is reacted in a solvent at an elevated temperature in the presence of a Lewis acid (as a catalyst) with an acyl chloride having the formula: ##STR3## wherein R has the same meaning as above. The reaction mixture is subsequently placed in an aqueous phase for hydrolysis. The 6-substituted-4-methyl-2-pyridone is separated by extraction through the buffering of the reaction mixture at a pH of 4 to 5.
    Type: Grant
    Filed: January 11, 1979
    Date of Patent: May 27, 1980
    Assignee: Lonza, Ltd.
    Inventor: Urs Michel
  • Patent number: 4192946
    Abstract: A process for the production of 3-hydroxy-5-chloropyridine and 3-hydroxy-5-bromopyridine is disclosed which process comprises reacting 2-furfurylamine in aqueous mineral-acid solution at -20.degree. to +5.degree. C. with chlorine or bromine, neutralizing the hydrohalic acid formed, heating the reaction mixture at reflux temperature, and isolating the formed 3-hydroxy-5-halopyridine. The 3-hydroxy-5-halopyridines obtained are intermediates for the production of insecticides.
    Type: Grant
    Filed: June 29, 1978
    Date of Patent: March 11, 1980
    Assignee: Ciba-Geigy Corporation
    Inventors: Niels Clauson-Kaas, Gunter Mattern, Walter Traber