Method for preparing chiral baclofen

A method for preparing (R)-Baclofen of formula (I),

• comprising the steps of:
• reacting p-chlorocinamic acid with a chiral auxiliary compound of formula II to form a compound of formula III;
• performing Michael addition of nitromethane to a compound of formula III to give a compound of formula IV via diastereomeric selection;
• performing hydrolysis of the compound of formula IV to obtain a compound of formula V and recover the chiral auxiliary compound of formula II;
• and reducing a nitro group of the compound of formula V to yield (R)-Baclofen of formula I,
• wherein R1 and R2 are independently a hydrogen atom, an alkyl group having 1 to 8 carbon atoms or an aryl group having 6 to 10 carbon atoms;
• R3 is an alkyl group having 1 to 8 carbon atoms or an aryl group having 6 to 10 carbon atoms;
• and X is N, O or S.