2-halogen-benzimidazole derivatives and insecticidal compositions containing them

摘要

1,146,059. 2-Halobenzimidazoles. AGRIPAT S.A. 5 Aug., 1966 [6 Aug., 1965], No. 35095/66. Heading C2C. [Also in Division A5] Novel 2-halobenzimidazoles of the formula wherein Hal represents chlorine or bromine; R represents a halogen atom, particularly chlorine or bromine, the methyl or methoxy group, the trifluoromethyl group, the benzoylamino group or a benzoylamino group substituted in the benzene nucleus by halogen or trifluoromethyl groups or an alkylsulphonylamino group; R 1 represents the phenyl radical or a phenyl radical substituted by halogen or trifluoromethyl groups; X represents an oxygen or sulphur atom, the -SO- or -SO 2 - group; R 2 represents hydrogen or a metal cation; n represents the number 0 or 1; and m represents a number from 0 to (4-n), whereby, however, the sum of m + n must be at least 1, and whereby, however, in the case of n meaning 0, at least one of the radicals R does not represent halogen or a methyl, methoxy or trifluoromethyl radical, are prepared (a) by reacting the corresponding 2-hydroxy benzimidazoles with phosphorus oxychloride or oxybromide; (b) by oxidizing the corresponding 2-mercapto benzimidazoles to sulphonic acids and reacting these with phosphorus oxychloride or pentachloride; or (c) by reacting the corresponding 2-mercapto benzimidazoles with chlorine or bromine, and if desired converting the product into a salt or into another compound of the above formula (e.g. by further chlorination). 2 - Mercapto - 4,6 - 7 - (31,41 - dichlorophenoxy)-benzimidazole which may be used in process (b) or (c) is prepared by reacting 3,5-dichloro-6- (31,41 - dichlorophenoxy) - 1,2 - phenylenediamine with CS 2 , CSCl 2 or thiourea, and 4,6- dichloro - 7 - (31- trifluoromethyl - 41 - chlorophenoxy) - 2 - hydroxybenzimidazole is prepared by reacting 3,5 - dichloro - 6 - (31 - trifluoromethyl - 41 - chlorophenoxy) - 1,2 - phenylenediamine with phosgene, urea or chlorocarbonic acid ester. o-Phenylene diamines of the formula wherein, when R 1 -X is a phenoxy or halogenated phenoxy radical m is at least 1, obtainable by conventional methods and used as precursors of the above benzimidazoles, are described.