Phosphonic acid dihalides - from (thio) phosphonic acids and a carbonyl halide

摘要

In a process for cpds. (I): (where R is 1-18C alkyl, 4-8C cycloalkyl, 2-18C-alkenyl, Ph, phenylalkyl oralkylphenyl (of 6-8C), all opt. substd. by Cl, Br, CN or acyloxy, and X is halogen) cpds. (II) or their salts or functional derivs. (where Y = O or S) are reacted with cpds. (III): (where n is 1 or 2) in the presence of cpds. having at least 1 Natom or tri- or penta-valent P which is linked (in the case of N) by 1-4 valencies or (in the case of P) by at least 3 valencies to organic radicals having up to 20C, two of the valencies may form a double bond or in the presence of amidated mono-, di- or tri-acids of tri- or pentavalent-P, the N atoms of which may carry 1-20C alkyl groups and whose organic radicals may contain up to 20C and optionally in the presence of a solvent. Intermediates for plant protection agents, ripening agents, ignifuges. Esp. intermediates for 2-chloroethane phosphonic acid and its derivs. and vinylphosphonic acid which may be used in its polymerised form to prevent corrosion in metals. Increased yields without purification of intermediates.