GB726936A - Improvements relating to quaternary phosphonium compounds and their use - Google Patents

Abstract

The invention comprises quaternary phosphonium compounds of the general formula <FORM:0726936/IV (b)/1> wherein A represents a halogen-substituted radical of the phenyl, diphenylyl or phenoxyphenyl series, Y represents an oxygen or sulphur atom, Z represents a low molecular alkylene radical (which means one containing 1 to 3 carbon atoms: it can be represented by -CH2-, -CH2-CH2-, -CH2-CH2-CH2-or -CH2-CH-CH3), n represents 0 or 1 and X represents halogen. Such compounds are obtained by reacting halogen methyl ethers of the general formula A-(Y-Z)n-CH2-O-CH2-X with triphenyl phosphine. As a modification a halomethyl ether of the general formula A-O-Z-CH2-O-CH2-X wherein A represents a monophenyl, diphenylyl or a phenoxyphenyl radical which contains no halogen or at most two halogen atoms, Z represents a low molecular alkylene radical and X represents halogen, is reacted with triphenyl phosphine to produce a quaternary phosphonium compound which is then treated with a halogenating agent. The halogenmethyl ethers can be obtained by reacting monohalogenohydrins with alkali metal salts of halogen-substituted aromatic hydroxyl or sulphydryl compounds of the phenyl, diphenyl or phenoxyphenyl series to give the corresponding aryloxy- or arylmercapto-alkanols. As monohalogeno-hydrins are specified glycol chlorohydrin, 1,2- or 1,3-propylene chlorohydrin, or the corresponding bromohydrins. The aryloxyalkanols can also be obtained by reacting the p corresponding phenolates with the appropriate alkylene oxides, e.g. ethylene oxide or 1,2- or 1,3-propylene oxide. Reaction of the aryloxy alkanols with formaldehyde or substances yielding it and with hydrogen halide yields halogenomethyl ethers of the first formula above wherein n equals 1. Halogenomethyl ethers of that formula wherein n equals 0 are obtained by reacting the appropriately substituted benzyl alcohol with formaldehyde or agents yielding it, and hydrogen halide. As halogenating agents in the modified method chlorine or bromine in the presence of catalysts such as iodine or iron salts, or, e.g., sulphuryl halides are mentioned. In examples: (1) 2,4-dichlorophenol and glycol chlorhydrin are reacted to give the hydroxyethyl-2,4-dichlorophenyl ether which is reacted with paraformaldehyde and hydrogen chloride to give 2,4-dichlorophenoxyethyl-chloromethyl ether. The latter reacted with triphenyl phosphine gives 2,4-dichlorophenoxyethoxy-methyltriphenyl phosphonium chloride. As alternative starting materials 4-chlorophenol or 2,5- or 3,4-dichlorophenol and 1,2-propylene chlorohydrin can be used; (2) a process is effected similarly to (1), using 2,4,5- or 2,4,6-trichlorophenol instead of 2,4-dichlorophenol; (3) 3,4-dichlorothiophenol and glycol chlorohydrin are reacted to give hydroxyethyl-3,4-dichlorophenyl thioether which on treatment with paraformaldehyde and hydrogen chloride gives 3,4-dichlorophenylmercaptoethyl chloromethyl ether. The latter is reacted with triphenyl phosphine to give 3,4-dichlorophenylmercaptoethoxy methyl triphenyl phosphonium chloride. The bromide can be obtained similarly; (4) a process similar to (3) using 4-chlorophenol instead of 3,4-dichlorophenol is performed; (5) b -hydroxyethyl-p-diphenylyl ether is reacted with paraformaldehyde and hydrogen chloride to give 4-phenylphenoxyethyl chloromethyl ether which is reacted with triphenyl phosphine to give 4-phenylphenoxyethoxy methyl triphenyl phosphonium chloride. Into the product, on treatment with chlorine in acetic acid, three atoms of chlorine per molecule are introduced; (6) 2-chloroxenoxyethyl alcohol (from the reaction of 3 - chloro - 4 - hydroxydiphenyl and ethylene chlorohydrin) is reacted with paraformaldehyde and hydrogen chloride. The 2-chloro-xenoxy-ethyl chloromethyl ether obtained is reacted with triphenyl phosphine to give 2-chloroxenoxyethoxymethyl triphenyl phosphonium chloride. 3,5-Dichloro-4-hydroxydiphenyl is an alternative starting material; (7) 2-phenylphenoxy-ethyl chloromethyl ether (from the reaction of the b -hydroxyethyl ether of 2-hydroxydiphenyl with paraformaldehyde and hydrogen chloride) is converted by reaction with triphenyl phosphine to 2-phenylphenoxyethoxymethyl triphenyl phosphonium chloride, which is then chlorinated as in (5); (8) 4-[chloromethoxy - (ethoxy)] - 41 - chlorodiphenyl ether (produced by reacting 4-(b -hydroxyethoxy)-41-chlorodiphenyl ether, paraformaldehyde and hydrogen chloride is reacted with triphenyl phosphine to give 4-(41-chlorophenoxy)-phenoxyethoxymethyl triphenyl phosphonium chloride, into which three atoms of chlorine per molecule are introduced by chlorination as in (1); (9) p-chlorobenzyl alcohol is reacted with paraformaldehyde and hydrogen chloride to give 4-chlorobenzyl chloromethyl ether which is converted to the quaternary phosphonium compound by reaction with triphenyl phosphine; (10) the same general reactions as in (9), with 3,4-dichlorophenol in place of p-chlorophenol are carried out; (11) 3-trifluoromethyl-4-chlorophenoxyethyl alcohol (obtained by reacting 3 - trifluoromethyl - 4 - chlorophenol with ethylene chlorohydrin) is reacted with paraformaldehyde and hydrogen chloride to give 3-trifluoromethyl-4-chlorophenoxyethyl chloromethyl ether which is converted to the quaternary compound by reaction with triphenyl phosphine. The products are useful in preventing attack on keratinous fibres by insects such as moths and beetle larv (see Group VIII).