Patent GB-615137-A (GB)
Title: Manufacture of amides of ª‡,ª‰-unsaturated carboxylic acids
Filed: 1946-07-27
Abstract: Amides of a ,b -unsaturated carboxylic acids of the general formula <FORM:0615137/IV(b)/1> where R1 and R2 are hydrogen or methyl, R3 is alkyl, R4 is hydrogen, halogen, methyl or methoxy and R5 is halogen, methyl or methoxy are prepared by acylating an amine, or a reactive derivative thereof <FORM:0615137/IV(b)/2> with an a ,b -unsaturated carboxylic acid, or reactive derivative thereof of the general formula <FORM:0615137/IV(b)/3> and isolating the neutral reaction product.  X and Y are reactive groups which are split off during the reaction as the compound XY and may be any one of the following pairs of radicals: hydrogen and hydroxyl, hydrogen and esterified hydroxyl, hydrogen and halogen, halogen and halogen.  Thus, when the free acid is heated with the amine X=OH, Y=H and XY=H2O.  Other such possible reactions are: an alkali metal salt of the acid reacts with a salt of the amine (e.g. X=ONa, Y=HCl.H, XY=NaCl+H2O); an acid halide or anhydride reacts with the amine (e.g. X=Cl, Y=H, XY=HCl), with a metallic compound of the amine (e.g. X=Cl, Y=Na, XY=NaCl), or in special cases with the hydrohalide of the amine (e.g. X=Cl, Y=HCl.H, XY=2HCl); an ester reacts with the amine (e.g. X=OCH3, Y=H, XY=CH3OH); finally, an amide reacts with an N-alkyl-arylamine or a salt thereof (e.g. X=NH2, Y=H, XY=NH3).  In a preferred modification a metallic salt of the acid reacts with a reactive carbamic acid derivative of the amine such as a carbamic acid halide (e.g. X=ONa, Y=C1-CO-, XY=NaCl+CO2).  Numerous N-alkyl-arylamines are specified, together with acid derivatives of crotonic acid.  Instead of starting from a ,b -unsaturated acids, it is possible to start from corresponding suitably substituted saturated acids which are converted into the acid amides and then converted into a ,b -unsaturated acids by known methods.  Amides of a ,b -unsaturated acids which are unsubstituted in the a -position, i.e. where R2 is hydrogen in the general formula may be prepared from corresponding acid amides which are substituted in the a -position by a group which is replaceable by hydrogen.  The desired products may also be prepared by first preparing the corresponding secondary aryl amine and subsequently alkylating this with, for example, dialkyl sulphates, alkyl halides or alkyl esters of arylsulphonic acids.  In examples: (1) crotonic acid-N-ethyl-o-toluidide is prepared from N-ethyl-o-toluidine and crotonyl chloride; (2) dimethylacrylic-acid-N-methyl-o-toluidide is prepared from sodium dimethylacrylate and chloroformic acid-N-methyl-o-toluidide; (3) dimethylacrylic-acid-N-methyl-o-toluidide is prepared from b -hydroxyisocalerianic-acid ethyl ester and N-methyl-o-chloraniline; (4) crotonic-acid-N-ethyl-m-toluidide is prepared from ethylidene-malonic-acid-monethyl - ester - chloride and N - ethyl - m - toluidine and (5) dimethylacrylic - acid - N - methyl-p-toluidide is prepared by treating dimethylacrylic - acid - p - toluidide sodium salt with dimethyl sulphate.  Other compounds which may be prepared are listed.ALSO:Amides of a , b , unsaturated carbocylic acids of the general formula  <FORM:0615137/VI/1>  Where R1 and R2 are hydrogen or methyl R2 is alkyl, R4 is hydrogen, halogen methyl, or methoxy and R5 is halogen, methyl or methoxy, act as fungicides and insect repellants.  The compounds are prepared by known methods. Numerous examples are given.