Patent number: 5139563
Abstract: Compounds of formula I ##STR1## wherein A is nitrogen or a group CR.sup.5 ;each of R.sup.1, R.sup.2 and R.sup.5 is, independently, hydrogen, halogen, formyl, cyano, carboxy, azido or optionally substituted alkyl, alkenyl, alkynyl, cycloalkyl, alkoxy, alkenyloxy, alkynyloxy, aryloxy, alkylthio, alkenylthio, alkynylthio, arylthio, alkylcarbonyl, alkoxycarbonyl, amino, aminoxy or dialkyliminoxy; andR is ##STR2## in which R.sup.3 is hydrogen, optionally substituted alkyl, alkenyl, alkynyl, cycloalkyl, heterocyclic or aryl, or COR.sup.8, R.sup.8 being hydroxy, alkoxy, carboxy, alkoxycarbonyl, amino or mono- or di- alkylamino; andR.sup.4 is a group COR.sup.6 wherein R.sup.6 is hydrogen, halogen, hydroxy, or optionally substituted alkoxy, alkenyloxy, alkynyloxy, cycloalkoxy, aryloxy, alkylthio, alkenylthio, alkynylthio, arylthio, aminoxy, dialkyliminoxy or amino, or R.sup.6 is a group OR.sup.7 in which R.sup.7 is an optionally substituted heterocyclic ring; or ##STR3## each of R.sup.9 and R.sup.
Type:
Grant
Filed:
May 30, 1990
Date of Patent:
August 18, 1992
Assignee:
Shell Research Limited
Inventors:
David P. Astles, Andrew Flood, Alastair McArthur, Trevor W. Newton, John E. Spencer, David C. Hunter