Patents by Inventor Kantilal B. Desai

Kantilal B. Desai 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: 5382725
    Abstract: 1,3-dihalobenzene, particularly 1,3-dichlorobenzene, is produced in high efficiency from a mixture containing the subject compound and its corresponding 1,4-isomer by a special process in which the dihalobenzene mixture is treated with polyethylene glycols of varying molecular weight and the resulting slurry is filtered to remove a complex of 1,4-dihalobenzene and polyethylene glycol as a solid and the 1,3-dihalobenzene as the filtrate.The 1,4-dihalobenzene complexed with the polyethylene glycol can be recovered by a flash distillation under vacuum and the residue containing the polyethylene glycol can be recycled.The purity of the 1,3-dihalobenzene obtained by this process can further be improved by subjecting the product obtained after the polyethylene glycol treatment to a low temperature crystallization process where 1,3-dihalobenzene can be selectively crystallized to a purity of above 99%.
    Type: Grant
    Filed: February 18, 1994
    Date of Patent: January 17, 1995
    Assignee: Standard Chlorine of Delaware Inc.
    Inventors: Jacob George, Kantilal B. Desai, Francis M. Schoeffler
  • Patent number: 4111962
    Abstract: 2-Phenylnaphtho[1,2-b]furan, 2-phenylnaphtho[2,1-b]-furan and derivatives thereof substituted in the phenyl ring by alkyl, halo or cyano are useful as antifertility agents, and are prepared by cyclization of a naphthyloxyacetophenone with a strong acid.
    Type: Grant
    Filed: September 19, 1973
    Date of Patent: September 5, 1978
    Assignee: Sterling Drug Inc.
    Inventors: Nathan N. Crounse, Kantilal B. Desai
  • Patent number: 3993645
    Abstract: Benzofurans, benzothiophenes, indoles, naphthofurans and benzofuranobenzofurans which are substituted by 4-vinylphenyl groups wherein the 2-position of the vinyl is substituted by a monovalent aromatic radical having one to three aromatic rings are optical brightening agents useful for whitening and brightening natural and synthetic fibers, papers, resins and the like. The compounds are conveniently prepared by interacting benzofurans, benzothiophenes, indoles, naphthofurans or benzofuranobenzofurans which are substituted by a p-tolyl group, with an aromatic aldehyde or preferably the anil derivative thereof.
    Type: Grant
    Filed: April 30, 1975
    Date of Patent: November 23, 1976
    Assignee: Sterling Drug Inc.
    Inventors: Nathan N. Crounse, Kantilal B. Desai
  • Patent number: 3974144
    Abstract: Benzofurans, benzothiophenes, and naphthofurans which are substituted by carboxystyrylphenyl groups and their corresponding esters and amides are optical brightening agents useful for whitening and brightening natural and synthetic fibers, papers, resins and the like. The compounds are conveniently prepared by interacting benzofurans, benzothiophenes or naphthofurans, which are substituted by a p-tolyl group, with an aromatic aldehyde or preferably the anil derivative thereof.
    Type: Grant
    Filed: November 19, 1973
    Date of Patent: August 10, 1976
    Assignee: Sterling Drug Inc.
    Inventors: Nathan N. Crounse, Kantilal B. Desai
  • Patent number: 3932301
    Abstract: Benzofurans, benzothiophenes, indoles, naphthofurans and benzofuranobenzofurans which are substituted by 4-vinyl-phenyl groups wherein the 2-position of the vinyl is substituted by a monovalent aromatic radical having one to three aromatic rings are optical brightening agents useful for whitening and brightening natural and synthetic fibers, papers, resins and the like. The compounds are conveniently prepared by interacting benzofurans, benzothiophenes, indoles, naphthofurans or benzofuranobenzofurans which are substituted by a p-tolyl group, with an aromatic aldehyde or preferably the anil derivative thereof.
    Type: Grant
    Filed: May 29, 1973
    Date of Patent: January 13, 1976
    Assignee: Sterling Drug Inc.
    Inventors: Nathan N. Crounse, Kantilal B. Desai