Abstract: The invention discloses a method of preparing a high chiral purity lactam intermediate D comprising a step of reducing a compound C to lactam intermediate D in a solvent by hydrogenation reduction using a heavy metal catalyst and a chiral inducer. Brivaracetam can be prepared in a single step using the lactam intermediate D. The synthesis route is short, reaction conditions are mild, post-treatment is simple, reaction yield is high, chiral selectivity is good, and production cost is low. The conversion rate of the compound C in the reaction is 81%, and the DE value of the compound D is more than 99.0%, which is suitable for industrial production.

Abstract: The invention discloses a method of preparing a high chiral purity lactam intermediate and brivaracetam. The invention provides a method of preparing a lactam intermediate compound represented by molecular formula D, the method comprising a step of reducing a compound C to a lactam intermediate D in a solvent by hydrogenation reduction using a heavy metal catalyst and a chiral inducer. Brivaracetam can be prepared with a single step using the lactam intermediate compound represented by molecular formula D of the present invention. The synthesis route is short, reaction conditions are mild, post-treatment is simple, reaction yield is high, chiral selectivity is good, and production cost is low. The conversion rate of the compound C in the reaction is 81%, and the DE value of the compound D is more than 99.0%, which is suitable for industrial production.