Patents by Inventor Thomas Lied

Thomas Lied 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).

  • Process for the production of 1,2-dithiolan-3-pentanoic acid (thioctic acid) and 8-hydrocarbylthio-6-oxooctanoic acid
    Patent number: 4966732
    Abstract: 1,2-Dithiolane-3-pentanoic acid (D,L-thioctic acid) of the formula ##STR1## is prepared by a process comprising (a) reacting a 2-(3-alkylthiopropionyl)-cyclopentanone-1 of the formula ##STR2## where R is a C.sub.1 -C.sub.4 alkyl, phenyl or benzyl in aqueous alkaline solution at a temperature of about 20.degree. C. to about 90.degree. C. to form the corresponding carboxylic acid of formula VI ##STR3## (b) reacting the compound of formula VI with an alkyl mercaptan at a temperature between -20.degree. C. and 0.degree. C. to form the corresponding thioketal of formula VII ##STR4## (c) reacting the compound of formula VII with sodium in liquid ammonia at temperature temperture between -60.degree. C. and -10.degree. C.
    Type: Grant
    Filed: July 15, 1987
    Date of Patent: October 30, 1990
    Assignee: Degussa Aktiengesellschaft
    Inventors: Guenes Giray, Klaus Huthmacher, Axel Kleemann, Thomas Lied
  • Intermediates for the production of 1,2-dithiolan acid (thioctic acid)
    Patent number: 4800044
    Abstract: Compounds of forumla XII ##STR1## wherein R.sub.1 is hydrogen and R.sub.
    Type: Grant
    Filed: July 15, 1987
    Date of Patent: January 24, 1989
    Assignee: Degussa AG
    Inventors: Guenes Giray, Klaus Huthmacher, Axel Kleemann, Thomas Lied
  • Process for the production of 1,2-dithiolan-3-pentanoic acid (thioctic acid) and intermediate compounds therefor
    Patent number: 4705867
    Abstract: 1,2-Dithiolane-3-pentanoic acid (D,L-thioctic acid) of the formula ##STR1## is prepared by a process comprising (a) reacting a 2-(3-alkylthiopropionyl)-cyclopentanone-1 of the formula ##STR2## where R is a C.sub.1 -C.sub.4 alkyl, phenyl or benzyl in aqueous alkaline solution at a temperature of about 20.degree. C. to about 90.degree. C. to form the corresponding carboxylic acid of formula VI ##STR3## (b) reacting the compound of formula VI with an alkyl mercaptan at a temperature between -20.degree. C. and 0.degree. C. to form the corresponding thioketal of formula VII ##STR4## (c) reacting the compound of formula VII with sodium in liquid ammonia at a temperature between -60.degree. C. and -10.degree. C.
    Type: Grant
    Filed: April 4, 1986
    Date of Patent: November 10, 1987
    Assignee: Degussa Aktiengesellschaft
    Inventors: Guenes Giray, Klaus Huthmacher, Axel Kleemann, Thomas Lied