抄録
A study was made on preparation of amphoteric surfactants by the reaction of 1- (2-hydroxyethyl) -2-undecyl-2-imidazoline (1) with ethyl acrylate. Imidazolines are easily hydrolyzed with water, especially in the presence of a base, to afford amidoamines. After (1) was hydrolyzed, the reaction mixture was allowed to react with ethyl acrylate and then saponified.
Only sodium salts of N- [N'- (2-carboxyethyl) -N'- (2-hydroxyethyl) aminoethyl] laurylamide (4) was obtained.
However, when the reaction of (1) with ethylacrylate was carried out in the presence of water, followed by saponification, ring cleavage of (1) occurred at 2, 3 position, different from hydrolysis of (1) where the cleavage occurred at 1, 2 position, to give sodium salts of N- [N'- (2-carboxyethyl) ami-noethyl] -N- (2-hydroxyethyl) laurylamide (5) and N- [N', N'-bis (2-carboxyethyl) aminoethyl] -N- (2-hydroxyethyl) laurylamide (6) as main products.
In case of the reaction of (1) with ethyl acrylate under unhydrous condition, 1- (ethylcarboxyethoxyethyl) -2-undecyl-2-imidazoline (7) was obtained as a major product, however, the reaction was rather slow, and gave sodium salt of N- [N'- (carboxyethoxyethyl) aminoethyl] laurylamide (8) and N- [N'- (2-hydroxyethyl) aminoethyl] -laurylamide (2) by saponification.
By the reaction of (7) with ethyl acrylate in the presence of water, followed by saponification, sodium salt of N- [N'- (carboxyethoxyethyl) -N'- (2-carboxyethyl) aminoethyl] laurylamide (9) was obtained.
