GB647215A - Improvements in or relating to the production of organic halides - Google Patents

Abstract

Halides of general formula R(XCH2Y)n, where X is oxygen or sulphur, Y chlorine or bromine, n an integer not greater than 3 and R is a substituted or unsubstituted aryl radical or, when X is sulphur and n is 1, may also be an aralkyl radical, are obtained by reacting a sulphuric acid of general formula R(XCH2SO3H)n, wherein R, X and n have the above values, or an alkali or alkaline earth metal salt thereof, with phosphorus pentachloride, pentabromide, oxychloride or oxybromide or thionyl chloride or bromide, in the presence or absence of an inert diluent. R may contain substituents which do not interfere with the reaction although known reactions such as RCOOH-->RCOCl may be carried out simultaneously. In examples, sodium 2 : 4-dichlorophenoxymethane sulphonate is reacted with phosphorus pentachloride in (1) and (2) at room temperature, and (3) in refluxing ether to give 2 : 4-dichlorophenoxymethyl chloride, 4-methoxyphenoxymethyl chloride is prepared by the method of (2) from the corresponding sodium sulphonate; in (4) and (5) the barium salt is used in place of the sodium salt of (2) and (3), reaction conditions being otherwise the same and, also in (4), 2-chlorphenoxymethyl chloride is prepared from the corresponding barium sulphonate; in (6) barium 2 : 4-dichlorphenoxymethane sulphonate is refluxed with phosphorus oxychloride to give 2 : 4-dichlorphenoxymethyl chloride and in a similar fashion the 2 : 5-dichloro-, 2 : 4 : 5-trichloro-, and 2 : 4 : 6-trichloro-substituted methyl chlorides are prepared from the corresponding barium sulphonates; (7) 2 : 4-dichloro- and (8) 4-chlorophenoxymethane sulphonic acid is refluxed with thionyl chloride to give the corresponding methyl chlorides; (9) 4-cyano-phenoxymethyl chloride is prepared from the corresponding sodium sulphonate in benzene solution as in (3); and in (10) the pentabromide is substituted for the pentachloride of (3) to give the corresponding bromide. Specification 647,214, which is referred to, describes and claims the preparation of the sulphonic acids and their salts, used as reactants. Samples have been furnished under Sect. 2 (5) of phenylene - 1 : 4 - bis - (oxymethyl chloride) obtained by refluxing barium phenylene - 1 : 4 - bis-(oxymethane sulphonic acid) in ether with phosphorus pentachloride, 4-methylphenylthiomethyl chloride by reacting sodium 4-methylphenylthiomethane sulphonate with phosphorus pentachloride, 4 : 6-dichlorophenylene-1 : 3-bis-(thiomethyl chloride) by heating sodium 4 : 6-dichlorophenylene - 1 : 3 - bis - (thiomethane sulphonate) with phosphorus pentachloride and oxychloride, 4-chlorophenylthiomethyl chloride by reacting sodium 4-chlorophenylthiomethane sulphonate with phosphorus pentachloride and benzylthiomethyl chloride by reacting sodium benzylthiomethane sulphonate with phosphorus pentachloride.