4-aza indole derivatives and their use as fungicides

1. A method of preventing and/or controlling fungal infection in plants and/or plant propagation material comprising applying to the plant or plant propagation material a fungicidally effective amount of a compound of formula (I):

wherein:

X 1 is CH;

X 2 is CH;

R 1 is hydrogen, methyl, or chloro;

R 2 is hydrogen or methyl;

R 3 is hydrogen, cyanomethyl, aminoethyl, aminopropyl, pro-2-enyl, pro-2-ynyl, propa-1,2-dienyl, methoxymethyl, 2-fluoroethyl, —OCH2CCH, —OCH2OCH3, —OCH2CN, —OCH(CH3)CN;

R 4 is phenyl or 4-fluorophenyl:

(iv)

(iii)

R 6 is hydrogen or —NHCOR 23 ;

R 7 and R 8 are hydrogen; and

R 23 is methyl, ethyl, isopropyl, methoxy, C2-6alkenyl, cyclopropyl, cyclobutyl, methylcyclopropyl or methylcyclobutyl

or a salt of N-oxide thereof.

2. The method of claim 1 , wherein R 1 is hydrogen.

3. The method of claim 1 , wherein R 2 is hydrogen.

4. The method of claim 1 , wherein R 3 is hydrogen.

5. The method of claim 1 , wherein the fungal infection is a Botrytis cinerea, Pyricularia oryzae, Fusarium culmorum, Septoria nodurum and Septoria tritici, Rhizoctonia solani, Puccinia recondite, Erysiphe graminis, Pyrenophora teres, Phytophthora infestans, Pythium ultimum or Plasmopara viticola infection.