Patents by Inventor Laszlo Levai

Laszlo Levai 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: 5216157
    Abstract: The invention relates to a process for the preparation of dimethyl-1,4-dihydro-2,6-dimethyl-4-(2'-nitro-phenyl)-pyridine-3,5-dicarbo xylate of the Formula I ##STR1## which comprises a) reacting a compound of the general Formula II ##STR2## (wherein n is 1 or 3; if n is 1, then R stands for a group of the Formula (a) ##STR3## and if n is 3, then R represents hydrogen) with methyl acetoacetate of the Formula IIICH.sub.3 --CO--CH.sub.2 --COOCH.sub.3 (III)and optionally with an amino compound of the general Formula IV ##STR4## (wherein Z is a group of the Formula (c), ##STR5## k is 1 and both symbols p are 0; or Z stands for a C.sub.
    Type: Grant
    Filed: April 17, 1991
    Date of Patent: June 1, 1993
    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: 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: 4259257
    Abstract: The invention relates to novel 1-phenyl-2-amino-1,3-propanediol-N-alkyl derivatives having the general formula I ##STR1## wherein R.sub.1 is hydrogen, alkyl having from 1 to 8 carbon atoms or phenoxymethyl, andR.sub.2 is hydrogen, alkyl having from 1 to 8 carbon atoms or 2,2-diphenylethyl,with the proviso that if R.sub.1 is phenoxymethyl then R.sub.2 may stand only for methyl, and if R.sub.2 is 2,2-diphenylethyl then R.sub.1 may stand only for hydrogen, and its isomers and pharmaceutically acceptable salts. Furthermore, the invention relates to a process for preparing these compounds.The novel 1-phenyl-2-amino-1,3-propanediol-N-alkyl derivatives having the general formula I possess significant anti-anginose activity and show several other biological activities.
    Type: Grant
    Filed: September 7, 1979
    Date of Patent: March 31, 1981
    Assignee: Egyt Gyogyszervegyeszeti Gyar
    Inventors: Laszlo Levai, Gabor Fazekas, Lujza Petocz, Katalin Grasser
  • Patent number: 4160035
    Abstract: A plant protecting composition with pesticidal effects contains an effective amount of at least one compound of the formula ##STR1## wherein R is a C.sub.1-20 alkyl group or a phenyl or phenyl-C.sub.1-3 alkylene group having optionally one or more C.sub.1-3 alkyl or halogen substituents on the phenyl ring, and a diluent in an amount necessary to make up the final weight of the composition. To kill plant pests, the composition is applied to growing plants either prior to or after emergence.
    Type: Grant
    Filed: November 3, 1977
    Date of Patent: July 3, 1979
    Assignee: Egyt Gyogyszervegyeszeti Gyar
    Inventors: Laszlo Levai, Gyula Mikite, Attila Kis-Tamas
  • Patent number: 4123615
    Abstract: The invention relates to a novel process for producing the threo- and erythro-isomers of 1-phenyl-2-nitro-1,3-propanediol through the aldol-type alkaline condensation of benzaldehyde and nitroethanol, wherein the reaction mixture is acidified and, if desired, the isomers are separated from the obtained isomer mixture and the obtained isomers are transformed into each other through epimerization, characterized in that the condensation and, if desired, also the epimerization are carried out in the presence of catalytical amounts of an alkaline hydroxide.The process according to the invention makes it possible to produce 1-phenyl-2-nitro-1,3-propanediol, an intermediate of the antibiotic chloramphenicol, in high yields, and in an extremely advantageous way which can be carried out simply and economically even on an industrial scale.
    Type: Grant
    Filed: February 23, 1977
    Date of Patent: October 31, 1978
    Assignee: Egyt Gyogyszervegyeszeti Gyar
    Inventors: Laszlo Levai, Gyula Mikite