The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 18, 1994
Filed:
Jul. 07, 1992
Stephen Kelly, Mohlin, CH;
Hoffmann-La Roche Inc., Nutley, NJ (US);
Abstract
Optically active compounds of the formula ##STR1## wherein rings A.sup.1 and A.sup.2 each independently signify pyridine-2,5-diyl, pyrimidine-2,5-diyl or 1,4-phenylene, which is unsubstituted or substituted with at least one of halogen, cyano and/or methyl; R.sup.1 and R.sup.2 each independently represent alkyl with 1 to 18 carbon atoms in which optionally 1 --CH.sub.2 -- group or 2 non-adjacent --CH.sub.2 -- groups is/are replaced by --O--, --COO-- and/or --OOC-- and/or one --CH.sub.2 --CH.sub.2 -- group can be replaced by --CH.dbd.CH--; with the proviso that at least one of the groups R.sup.1 and R.sup.2 must be chiral, liquid crystalline mixtures which contain these compounds and their use for optical and electro-optical purposes.