Disclosed is a compound of formula I, wherein R1 is hydrogen, hydroxyl, halo, cyano, C1-8 alkyl, C1-8 haloalkyl, C1-8 alkoxy, C1-8 haloalkoxy, C1-8 alkylthio or C3-10 cycloalkyl； R2 is hydrogen, hydroxyl, halo, C1-8 alkyl, C1-8 alkoxy, C1-8 alkenyloxy or C1-8 alkynyloxy, C3-10 cycloalkyl； R3, R4, R5 and R6 are, independently, hydrogen, hydroxyl, halo, cyano, nitro, amino, mono- and bis-C1-8 alkyl amino, C1-8 alkyl, C2-8 alkenyl, C2-8 alkynyl, C1-8 haloalkyl, C1-8 alkoxy, C1-8 haloalkoxy, C1-8 alkylthio or C3-10 cycloalkyl； A is halo, C1-10 alkyl, C2-10 alkenyl, C2-10 alkynyl, C1-8 haloalkyl, C1-8 alkoxy, C3-10 cycloalkyl, C3-10 cycloalkyloxy, aryl, arylalkyl, aryloxy, arylalkyloxy or arylthio； or a salt or a N-oxide thereof, provided that if A is methyl and each R1, R3, R4, R5 and R6 is hydrogen R2 is not chlorine, such as 2-(5-methyl-6-o-tolylpyridin-2-yl)-quinazoline and 2-[6-(4-fluoro-3-methylphenyl)-5-methylpyridin-2-yl]-quinazoline. Also disclosed is a process for the preparation of a compound of formula I, wherein R2 is hydrogen.
