Method for preparing C-H acidic (meth)acrylates

A method for preparing C—H acidic (meth)acrylates of formula (I):

• CH2═CR1—CO—NH—R2—NH—CO—CH2—CN (I)
• (P)
• wherein:
• R1 is H or methyl;
• R2 is CnHmOxNy;
• wherein:
• n=2-15;
• m=4-30;
• x=0-4;
• and
• y=0-4;
• wherein said method comprises:
• a) reacting an ester of cyanoacetic acid (A) with a diamine (B) in excess;
• b) removing unreacted diamine (B) from the reaction solution to obtain the intermediate product (IP), an amino-functionalized cyanoacetamide;
• c) obtaining product (P) by reacting intermediate product (IP) obtained in step b) with either:
• c1) (meth)acrylic acid esters (MAD);
• or
• c2) (meth)acrylic anhydride (MAD) or (meth)acryloyl halide (MAD);
• d) optionally isolating (P) by extraction or crystallization.