New halo-alkoxy-or substd. 2-pyridyl-4-phenyl-benzoxazine cpds. - useful as fungicides for plant protection

摘要

2-Pyridyl-4-substd. phenyl -benzo(d)oxazine cpds. of formula (I), their acid addn. salts and metal salt complexes are new. In (I), Py = 4-pyridyl; Ar = R5, R6, R7, R8, R9-phenyl; R1-R9 are each H, halo, NO2, alkyl, alkoxy, alkylthio, haloalkyl, haloalkoxy or haloalkylthio but at least one of them must be haloalkoxy or haloalkylthio. USE/ADVANTAGE - (I) are pesticides with better fungicidal activity than known cpds. of similar structure. They are well tolerated, can be applied to plants, seeds or the soil, and give esp. good results against Cochliobolus satives, Pyrenophora teres, Pyricularia oryzae and venturia inaequalis. In an example, a mixt. of 64g N-(2-(4-CF3O-alpha -hydroxybenzyl)phenyl) -pyridine-4-carboxamide, 1.4ml SOCl2 and 95ml pyridine was stirred for 16 hrs. room temp., then poured into 500ml water and extracted several times with ethyl acetate. The extract was dried, evaporated and the oily residue digested with diisopropyl ether to give 1.8g (27%) of 4-(4-CF3O-phenoxy)-2 -(4-pyridyl)-4H-benzo(d)oxazine.