TETRAHYDROPYRIDO [2, 3-B] PYRAZINE AND DIHYDROPYRIDO [2 , 3-B] PYRAZINE DERIVATIVES AS PLANT FUNGICIDES

摘要

The present invention relates to novel tetrahydropyrido[2,3-b]pyrazine and dihydropyrido[2,3-b]pyrazine derivatives of formula I as active ingredients which have microbiocidal activity, in particular fungicidal activity: formula (l) wherein R<SUP>1</SUP> is for example halogen; R<SUP>2</SUP> is for example optionally substituted aryl or heteroaryl; R<SUP>3</SUP> and R<SUP>4</SUP>, each independently of each other, are for example hydrogen, halogen or cyano; or R<SUP>3</SUP> and R<SUP>4</SUP> together with the nitrogen atom to which they are attached form an optionally substituted heterocylic ring; R<SUP>5 </SUP>and R<SUP>8</SUP>, each independently of other, are for example hydrogen, C<SUB>1</SUB>-C<SUB>6</SUB>alkyl or C<SUB>1</SUB>-C<SUB>6</SUB>haloalkyl; R<SUP>6</SUP> and R<SUP>7</SUP>, each independently of each other, are for example hydrogen, C<SUB>1</SUB>-C<SUB>6</SUB>alkyl or C<SUB>1</SUB>-C<SUB>6</SUB>haloalkyl; or R<SUP>6</SUP> is part of an endocyclic C=N double bond together with R<SUP>5</SUP> on the adjacent nitrogen atom; or R<SUP>6</SUP> is part of an endocyclic C=C double bond together with R<SUP>7</SUP> on the adjacent carbon atom; or R<SUP>7</SUP> is part of an endocyclic C=N double bond together with R<SUP>8</SUP> on the adjacent nitrogen atom.