Patents Examined by John D. Peabody, II
  • Process for the preparation of symmetrical 2,2-methylenebisbenzotriazolyl phenols
    Patent number: 5229521
    Abstract: Compounds of formula ##STR1## wherein R.sub.1 is hydrogen alkyl, alkoxy, phenyl, phenylaklyl or halogen, and R.sub.2 is alkyl phenyl, phenylaklyl or cycloalkyl, are prepared by reacting a compound of formula ##STR2## with a compound of formula ##STR3## wherein R.sub.3 and R.sub.4 are alkyl, and formaldehyde, in a one-pot process in the absence of a solvent.
    Type: Grant
    Filed: October 23, 1992
    Date of Patent: July 20, 1993
    Assignee: Ciba-Geigy Corporation
    Inventors: Reto Luisoli, Werner Stegmann