Patent GB-863434-A (GB)
Title: Phosphonic and thiophosphonic acid esters
IPC: C07F9/40
Filed: 1958-05-30
Abstract: The invention comprises phosphonic acid esters of the general formula:  <FORM:0863434/IV (b)/1> in which R and R1 are C1-C4 alkyl radicals R2 is an alkyl, cycloalkyl, aralkyl, or aryl radical or a substitution product thereof, and X, Y and Z are oxygen or sulphur. R2 is preferably an alkyl radical containing up to 12 carbon atoms, an alkylmercaptocyano-, halogenphenyl-, halophenyl-, or phenylmercaptosubstituted alkyl radical, or a cycloalkyl, phenyl, halo-substituted phenyl, nitrosubstituted phenyl, alkyl mercapto substituted phenyl, alkyl substituted phenyl or chromanyl radical (i.e. the radical derived from dihydrobenzo-pyran).  The products or certain types of the products may be obtained by various methods. Thus an ether RO (or S)-CH=CH2 may be reacted with PCl5 to form adducts which are then reacted with sulphurous acid to form the dichlorides of the type RO (or S) CH=CH-P(O)Cl2 which are then reacted with an alochol R1OH to form the product of the type RO (or S) CH=CH.P(O)(OR1)2.  Alternatively, can be converted to the ester chloride by reaction with an alcohol R1OH and the ester chloride then reacted with the same or different alcohol or with a phenol, mercaptan or thiophenol (HZR2).  Also, the diesters may be reacted with phosgene to form the corresponding ester chlorides RO (or S) CH=CH.P(O) (OR1) Cl and these products may be reacted with alcohols, mercaptans, phenols or thiophenols to form products of the type RO (or S) CH=CH-P(O)(OR1)(ZR2).  The phosphorus pentachloride adducts referred to above may also be reacted with hydrogen sulphide to form products of the type RO (or S) CH= CH-P(S)Cl2 which may be reacted with an alcohol R1OH to form compounds of the type RO (or S) CH=CH-P(S)(OR1) Cl which can be condensed with an alcohol, mercaptan, phenol or thiophenol to form products of the type RO (or S) CH=CH P(S)(OR1)(ZR2).  The condensation of the phosphonic or thiophosphonic acid chlorides with alcohols or phenols may be carried out in the presence of an acid-binding agent, e.g. a tertiary amine, and in the presence of an inert solvent, or the phenols may be used in the form of their alkali metal salts.  When the thionophosphonic monochlorides are saponified with alkaline reacting compounds, e.g. potassium hydroxide, chlorine is eliminated with formation of products of the type RO (or S) CH=CH P(S)(OR1)(OH) which react in their tautomeric thiolo form with aliphatic, aliphatic-aromatic and in some cases aromatic halides to form esters of the formula RO (or S) CH=CH P(O)(OR1)(SR2) the reaction being generally carried out at elevated temperature.  When the phosphonic acid ester monochlorides are reacted with mercaptans the latter are generally used in the form of their salts, e.g. alkali metal salts, or when the b -alkoxy- (or b -alkylmercapto-)-vinyl-thionophosphonic ester monochlorides are reacted with a mercaptan the reaction is expediently carried out at 20-40 DEG C in the presence of an alkali metal alcoholate, e.g. sodium ethylate as an acid binding agent and an inert solvent may be present.  The products have insecticidal properties (see Group VI) and several examples for their production are given.  Specified products include those of the above general formula in which X is oxygen, Y is oxygen or sulphur, R1 is ethyl and ZR2 is S.CH2CH2SC2H5, and a compound of the formula:  <FORM:0863434/IV (b)/2> The compound C2H5OCH=CH.P(O)(OC2H5) Cl which may be used as an intermediate in the preparation of the products may be obtained by reacting b -ethoxy-vinyl-phosphonic acid diethyl ester with phosgene at 65-70 DEG C.ALSO:An insecticidal composition comprises one or more phosphonic acid esters of the general formula <FORM:0863434/VI/1> wherein R and R1 are alkyl radicals containing up to 4 carbon atoms, R2 is an alkyl, cycloalkyl, aralkyl, or aryl radical, or a substitution product thereof and X, Y and Z are oxygen or sulphur (see Group IV (b)) and an inert solid or liquid carrier or diluent. The radical R2 is preferably an alkyl radical containing up to 12 carbon atoms, or an alkyl radical substituted by an alkylmercapto, dialkylamino, carbalkoxy, cyano, halogen, phenyl, halophenyl, or phenylmercapto radical, or is cycloalkyl, phenyl, halophenyl, nitrophenyl, alkylmercaptophenyl, alkylphenyl or chromanyl (the radical derived from dihydrobenzo-pyran).  Specified  carriers or diluents are talc, chalk, bentonite, clay, alcohols, ketones and liquid hydrocarbons. Known insecticides and/or fertilizers may also be present.  A suitable composition is obtained by mixing the active ingredient with dimethyl formamide, adding benzyl hydroxy diphenyl polyglycol ether as emulsifier and diluting with water.