Process for preparing brivaracetam
The present invention relates to a new process for preparing brivaracetam. (Ib)
1. A process for the preparation of (2S)-2-[(4R)-2-oxo-4-propyltetrahydro-1H-pyrrol-1-yl]butanamide (brivaracetam) in an enriched amount ranging from a 78.5/21.5 to 83/17 ratio in favor of the brivaracetam diastereomer, through catalytic reduction performed according to the following reaction:
whereby the Catalyst is either of the following:
Pt/C; with the addition of formic acid or citric acid;
Pd/C; with the addition of citric acid or formic acid;
Ir/CaCO 3 with the addition of formic acid or citric acid.
2. The process according to claim 1 , wherein the Catalyst is either of the following:
Pt/C; with the addition of formic acid;
Pd/C; with the addition of citric acid;
Ir/CaCO 3 with the addition of formic acid.
3. The process according to claim 1 , which is performed in a polar solvent or in a polar aprotic solvent or in an apolar solvent.
4. The process according to claim 3 , which is performed in water.
5. The process according to claim 1 , wherein the hydrogen pressure is usually adjusted at any value between 5-40 bars.
6. The process according to claim 1 , wherein Pt/C; with the addition of formic acid, in an amount of 2 eq is used as catalytic system (Catalyst).
7. The process according to claim 1 , wherein Pd/C; with the addition of citric acid, in an amount of 2 eq is used as catalytic system (Catalyst).
8. The process according to claim 1 , wherein Ir/CaCO 3 with the addition of formic acid, in an amount of 2 eq is used as catalytic system (Catalyst).
9. A process for the preparation of an essentially pure (2S)-2-[(4R)-2-oxo-4-propyltetrahydro-1H-pyrrol-1-yl]butanamide (brivaracetam) having a ratio of at least 97/3, through catalytic reduction performed according to claim 1 followed by a MCC.