Process for the synthesis of ivabradine and addition salts thereof with a pharmaceutically acceptable acid

A process for the synthesis of ivabradine of formula (I):

• wherein a compound of formula (V):
• is subjected to a reductive amination reaction with an amine of formula (VI):
• in the presence of formic acid in an amount greater than 1 equivalent per equivalent of aldehyde
• and of triethylamine in an amount greater than 1 equivalent per equivalent of aldehyde,
• at a temperature from 15 to 100° C.,
• in the absence of solvent or in an alcoholic solvent.