Patent GB-631738-A (GB)
Title: Preparation of amphoteric amides of acrylic acid and their polymers
IPC: C08F20/52
Filed: 1946-10-02
Abstract: Polymerized amphoteric amides are prepared by the polymerization of acrylamide- or a -substituted b  - unsubstituted acrylamidoaliphatic amino carboxylic acids containing at least one primary or secondary amino group and a free carboxylic group in the aliphatic amino carboxylic acid group, or of compositions containing such amides. The a -substituent may be an aliphatic radical for example methyl, ethyl, propyl, butyl or amyl, a cycloaliphatic radical for example cyclohexyl, an aryl or aralkyl radical for example phenyl or benzyl, or a halogen atom such as chlorine or bromine.  The monomers may be interpolymerized with other polymerizable compounds containing a CH2=C< group such as methacrylamide, methacrylic acid, methyl methacrylate, vinyl acetate, vinyl ketone, vinyl chloride and butadiene. Polymerization may be affected by standing at room temperature or by means of ultra-violet light or a polymerization catalyst such as benzoyl peroxide.  It may be carried out in bulk, in aqueous alcohol solution or in water.  The polymers, stated to be novel, have a protective-colloid action and may be used as a substitute or modifier for gelatine.  Examples describe the polymerization of N-methacrylyllysine and acrylyl-lysine, alone or with water, methanol or isopropanol, the polymerization of a mixture of methacrylamide and methacrylyl-lysine and the polymerization of monomers obtained by interaction of equimolecular proportions of acrylyl or methacrylyl chloride with the hydrochlorides of a  : b -diamino propionic acid, the a  : b -, a  : g - and b  : g -diamino-butanoic acids and a  : b -diamino-pentanoic acid. Polymerizable monomers may also be obtained from a  : b -diamino-pentanoic acid The preparation of the monomers is described (see Group IV (b)).ALSO:Amphoteric amides of the acrylic acid series are prepared by reacting an acrylic or a -substituted b -unsubstituted acrylic acid halide or anhydride with an aliphatic polyamino carboxylic acid, or acid salt thereof, in which the amino groups are primary or secondary, the acid halide or anhydride being employed in a molar amount, per mole. of amino acid, which is less than the number of amino groups in the amino acid.  Alternatively, the amphoteric amides may be prepared by reacting the polyamino carboxylic acid or acid salt thereof with b -halo-propionic acid halide or anhydride thereof or an a -substituted derivative thereof, in the same manner to obtain a b -halo-propionamide which is then dehydrohalogenated by heating with an aqueous alkaline reacting salt. Preferably, the reactants are employed in equimolecular proportions and in the presence of alkali such as sodium or potassium hydroxides or pyridine to neutralize acid formed in the reaction.  The reaction is normally carried out at 0 DEG  to - 10 DEG  C.  The amides may be isolated by treating the reaction product with solvents in which the salts formed in the reaction are insoluble, for example, methanol and acetone, and then precipitating the amides by addition of a non-solvent therefor.  The amides contain free amino and carboxylic groups and they may be polymerized (see Group IV (a)) and the polymerized products may be used as gelatin substitutes or gelatin-modifiers. In examples: (1) methacrylyl chloride and aqueous sodium hydroxide are added dropwise to an ice-cooled suspension of dl-lysine hydrochloride in water and the product worked up for isolation of N - methacrylyl - lysine; corresponding compounds may be prepared similarly from a  : b -diamino-propionic acid, the a  : b -, a  : g - and b  : g -diamino-butanoic acids and a  : d -diamino-pentanoic acids; (2) dl-lysine hydrochloride is treated with silver acetate in aqueous solution, the mixture filtered and the filtrate reacted with methacrylic anhydride in presence of caustic soda; the product is filtered, extracted with acetone and methacrylyl lysine precipitated by addition of ether and methanol; (3) acrylyl chloride is reacted as in (1) with dl-lysine hydrochloride to yield acrylyl-lysine, or with the other amino acids specified in (1); (4) dl-lysine hydrochloride and a  : b -dichloro propionyl chloride are reacted in presence of sufficient sodium hydroxide to neutralize the acid formed, by the method of (1), and the resulting a  : b -dichloro propionyl lysine heated with aqueous sodium acetate to form a -chloroacrylyl-lysine.  As additional starting materials there may be used b -unsubstituted acrylic acid halides or anhydrides containing as a -substituents such aliphatic radicals as ethyl, propyl, butyl or amyl, cycloaliphatic radicals such as cyclohexyl, aryl or aralkyl radicals such as phenyl or benzyl, and halogen atoms such as bromine, and a  : b -diamino pentanoic acid.  The amino carboxylic acids may be used in the form of their dl-, d- or loptical isomers.