Patents by Inventor Hans-Joachim Zeiss

Hans-Joachim Zeiss 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 preparation of L-homoalanin-4-yl(methyl)-phosphinic acid and its alkyl esters
    Patent number: 4777279
    Abstract: Process for the preparation of L-homoalanin-4-yl(methyl)-phosphinic acid (esters) of the formula I ##STR1## (R, R.sub.1 =H, alkyl) or salts thereof by reacting an R-3-isopropyl-2,5-dialkoxy-3,6-dihydropyrazine of the formula II with a .beta.-halogenoethyl(methyl)phosphinic acid ester of the formula IV ##STR2## (R', R.sub.1 '=alkyl) to give compounds of the formula V ##STR3## and then subjecting the latter to hydrolytic cleavage.
    Type: Grant
    Filed: December 1, 1986
    Date of Patent: October 11, 1988
    Assignee: Hoechst Aktiengesellschaft
    Inventor: Hans-Joachim Zeiss
  • Phosphorus-containing .alpha.-amino nitriles and a process for their preparation
    Patent number: 4692541
    Abstract: A process for the preparation of phosphorus-containing .alpha.-amino nitriles of the general formula I ##STR1## in which R.sub.1 and R.sub.2 denote (substituted) alkyl, aryl, aralkyl or cycloalkyl, R.sub.3 denotes H, alkyl, phenalkyl, acyl, alkoxycarbonyl or aryloxycarbonyl, and n denotes zero or one, by reaction of corresponding acylals with alkali metal cyanides under the conditions of the Strecker synthesis.
    Type: Grant
    Filed: March 7, 1986
    Date of Patent: September 8, 1987
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Hans-Joachim Zeiss, Hilmar Mildenberger