2-pyridylmethylamine derivatives useful as fungicides

A compound of formula I or a salt thereof

• wherein A1 is a 2-pyridyl group having substituents at the three or five position, or both, and at no other position, R1 and R2 are hydrogen, L is —(C═O)—, —SO2— or —(C═S)— and A2 is substituted phenyl,
• wherein any A1 substituent is selected from the group consisting of halogen, hydroxy, cyano, nitro, SF5, trialkylsilyl, optionally substituted amino, E, OE or SE, where E is alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkenyl, phenyl, each of which is optionally substituted, or —C(E)═N—Q, where Q is E, OE, SE or optionally substituted amino, and
• wherein the optional substituent
• when present on any alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkenyl or cycloalkynyl moiety is selected from the group consisting of halogen, cyano, alkoxy, alkylthio, mercapto, hydroxy, nitro, amino, acyl, acyloxy, acylthio, phenyl, phenylthio, phenoxy,
• when present on any cycloalkyl, cycloalkenyl or cycloalkynyl is an alkyl, alkenyl or alkynyl,
• when present on any phenyl group are selected from the same group as the A1 substituents, and
• when present on any amino group is E or acyl.