Patents by Inventor Balwant Singh

Balwant Singh 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: 3944619
    Abstract: D-2-Amino-1-butanol, for the synthesis of ethambutol hydrochloride, d,d'-2,2'-(ethylenediimino)di-1-butanol dihydrochloride, is produced in high purity and good yields by the reaction of butene-1, a nitrile, preferably an excess of acetonitrile, and chlorine to form N-[1-(chloromethyl)propyl]acetimidoyl chloride which is hydrolyzed to dl-2-amino-1-butanol, which can be isolated as the hydrochloride, or free base, or a mixture, resolved with L(+)- tartaric acid and the d-2-amino-1-butanol reacted with ethylene dichloride and then hydrochloric acid to form ethambutol hydrochloride. A minimum of by-products which are conveniently split out permits the economical synthesis of a pharmaceutical grade product.
    Type: Grant
    Filed: August 1, 1974
    Date of Patent: March 16, 1976
    Assignee: American Cyanamid Company
    Inventor: Balwant Singh
  • Patent number: 3944617
    Abstract: DL-2-Amino-1-butanol, as the free base or a salt, for resolution to d-2-amino-1-butanol, for the synthesis of ethambutol hydrochloride, d,d'-2,2'-(ethylenediimino)di-1-butanol dihydrochloride, is produced in high purity and good yields by the reaction of butene-1, a nitrile, preferably an excess of acetonitrile, and chlorine to form N-[1-(chloromethyl)propyl]acetimidoyl chloride which is hydrolyzed to dl-2-amino-1-butanol hydrochloride. This can be isolated as the hydrochloride, or free base, or a mixture, resolved with L(+)- tartaric acid and the d-2-amino-1-butanol reacted with ethylene dichloride and then hydrochloric acid to form ethambutol hydrochloride. A minimum of by-products which are conveniently split out permits the economical synthesis of a pharmaceutical grade product.
    Type: Grant
    Filed: August 1, 1974
    Date of Patent: March 16, 1976
    Assignee: American Cyanamid Company
    Inventor: Balwant Singh
  • Patent number: 3944618
    Abstract: D-2-Amino-1-butanol, for the synthesis of ethambutol hydrochloride, d,d'-2,2'-(ethylenediimino)di-1-butanol dihydrochloride, is produced in high purity and good yields by the reaction of butene-1, a nitrile, preferably an excess of acetonitrile, and chlorine to form N-[1-(chloromethyl)propyl]acetimidoyl chloride which is hydrolyzed to dl-2-amino-1-butanol, which can be isolated as the hydrochloride, or free base, or a mixture, resolved with L(+)-tartaric acid and the d-2-amino-1-butanol reacted with ethylene dichloride and then hydrochloric acid to form ethambutol hydrochloride. A minimum of by-products which are conveniently split out permits the economical synthesis of a pharmaceutical grade product.
    Type: Grant
    Filed: August 1, 1974
    Date of Patent: March 16, 1976
    Assignee: American Cyanamid Company
    Inventor: Balwant Singh
  • Patent number: 3933497
    Abstract: Dry photoimaging processes and compositions employing photosensitive coatings of volatile peri-substituted aromatic azido compounds in a permeable film-forming plastic are disclosed.
    Type: Grant
    Filed: June 27, 1974
    Date of Patent: January 20, 1976
    Assignee: American Cyanamid Company
    Inventor: Balwant Singh