Amino and imino propionic acids, process of preparation and use

A process for producing N-alkenyl amino or imino propionic acids to obtain a corrosion inhibiting compound consisting of N-alkenyl amino or imino propionic acids having the formula III and IV from a reaction that takes place in the absence of solvent, in the absence of a base, and at atmospheric pressure, said process comprising reacting an alkyl, alkenyl, cycloalkyl or aromatic amine of formula I with an alpha-beta unsaturated carboxylic acid of formula II according to the following synthesis scheme (3) in the absence of a solvent and in the absence of an alkali metal or organic base in an amine-acid ratio of 0.5:3 to 3:0.5 to obtain the N-alkenyl amino or imino propionic acids of formula III and/or IV

• the reaction being carried out at a temperature range of 90 to 100° C. and a reaction time between 1 and 10 hours by adding said compound of formula II in the absence of a solvent, in the absence of a base, and at atmospheric pressure, and then increasing the reaction temperature up to 160° C., where R is an alkenyl group having 1 to 30 carbon atoms, R1 is H or —CH3 and R2 is H;
• and
• removing unreacted amines by extraction with a hydrocarbon solvent to obtain said compounds III and IV.