Patents by Inventor Srinivasachari Rajappa

Srinivasachari Rajappa 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: 5750757
    Abstract: A process for the preparation of an S-alkyl ester of an N-alkyl carbamothioic acid having the formula: ##STR1## wherein R and R.sub.2 are each an alkyl group and R.sub.1 is hydrogen or alkyl, which includes refluxing the corresponding alkyl ester of N-alkyl thiocarbamio acid having the formula I ##STR2## wherein R and R.sub.2 are each alkyl and R.sub.1 is hydrogen or alkyl, in the presence of an acid catalyst selected from the group consisting of iodine and sulfuric acid.
    Type: Grant
    Filed: October 29, 1996
    Date of Patent: May 12, 1998
    Assignee: Council of Scientific and Industrial Research
    Inventors: Abdul Rakeeb Abdul Subhan Deshmukh, Rajan Hiralal Naik, Sagun Kashinath Tandel, Srinivasachari Rajappa
  • Patent number: 5621132
    Abstract: A process for the preparation of alkyl esters of N-alkyl or N-aryl thiocarbamic acid having the formula: ##STR1## wherein R is alkyl or aryl, R.sub.2 is alkyl and R.sub.1 is hydrogen or alkyl which comprises reacting the S-alkyl ester of N-alkyl or aryl dithiocarbamic acid having the formula: ##STR2## wherein R, R.sub.1, R.sub.2 have the meanings stated above with an appropriate alkali metal alkoxide in the presence of one or more alcoholic solvents.
    Type: Grant
    Filed: August 4, 1995
    Date of Patent: April 15, 1997
    Assignee: Council of Scientific and Industrial Research
    Inventors: Abdul R. A. S. Deshmukh, Rajan H. Naik, Sagun K. Tandel, Srinivasachari Rajappa
  • Patent number: 5066819
    Abstract: The invention relates to a process for the preparation of aryl esters of N-alkyl carbamic acids. The process comprises reacting an alkyl N-alkyl carbamate of the general formula:R.sub.1 --NH--COO--R.sub.3wherein R.sub.1 and R.sub.3 are both alkyl groups, with a substituted phenol in the presence of a halogen-containing phosphorous compound to produce an aryl ester of N-alkyl carbamic acid having the general formula:R.sub.1 --NH--COO--R.sub.2wherein R.sub.1 is an alkyl group and R.sub.2 is an aryl group derived from the substituted phenol. In a preferred embodiment of the invention, the process is used for the preparation of aryl esters of N-methyl carbamic acid.
    Type: Grant
    Filed: March 20, 1990
    Date of Patent: November 19, 1991
    Assignee: Council of Scientific & Industrial Research
    Inventors: Gurunath H. Kulkarni, Rajan H. Naik, Srinivasachari Rajappa
  • Patent number: 4967007
    Abstract: A process is disclosed for the manufacture of 1-substituted amino-1-substituted thio-2 nitro alkenes of the general formula: (R1NH) (R2S) C.dbd.CR3 (NO2) wherein R1, R2, R3, may be same or different and may consist of hydrogen, alkyl, aryl or arylalkyl groups or combinations thereof. These alkenes are prepared by reacting a primary amine with a compound of sulfur in the presence of a primary catalyst to obtain a carbonimidodithioic acid salt which is converted to a corresponding ester which is thereafter reacted with a nitro compound in the presence of a secondary catalyst. 1-methylamino-1-methylthio-2-nitroethene is an important intermediate in the synthesis of Rantitidine and Nizatidine which are used as effective drugs in the treatment of peptic ulcers and associated gastrointestinal disorders.
    Type: Grant
    Filed: May 16, 1989
    Date of Patent: October 30, 1990
    Assignee: Council of Scientific & Industrial Research
    Inventors: Abdul R. A. S. Deshmukh, Baburao M. Bhawal, Vasudeo P. Shiralkar, Srinivasachari Rajappa
  • Patent number: 4386097
    Abstract: The invention relates to 2-carboethoxyamino-5(6)-(2-amino-5-thiazoloyl)-benzimidazole compounds with anthelmintic properties and to processes for their preparation and pharmaceutical preparations containing such compounds.
    Type: Grant
    Filed: July 29, 1981
    Date of Patent: May 31, 1983
    Assignee: Ciba-Geigy Corporation
    Inventors: Srinivasachari Rajappa, Vasudevan Sudarsanam
  • Patent number: 4297365
    Abstract: The invention relates to 2-carboethoxyamino-5(6)-(2-amino-5-thiazoloyl)-benzimidazole compounds with anthelmintic properties and to processes for their preparation and pharmaceutical preparations containing such compounds.
    Type: Grant
    Filed: July 26, 1979
    Date of Patent: October 27, 1981
    Assignee: Ciba-Geigy Corporation
    Inventors: Srinivasachari Rajappa, Vasudevan Sudarsanam
  • Patent number: 4150229
    Abstract: 2,5-di-(.omega.-aminoalkyl-1')-pyrazines are obtained by catalytic hydrogenation of nitro compounds of the formula ##STR1## They are suitable as hardeners for epoxides or for the manufacture of polyamides.
    Type: Grant
    Filed: December 27, 1977
    Date of Patent: April 17, 1979
    Assignee: Ciba-Geigy Corporation
    Inventors: Srinivasachari Rajappa, Helmut Zondler