1. A process for the preparation of brivaracetam having the structure:
Di Lvamuemm comprising :
a) reacting (S)-3-(2-amino-2-oxoethyl) hcxanoic acid having the staicture (II):
with a chlorinating agent selected from the group consisting of trichloroisocyanuric acid, sodium dichloroisocyanurate and N-chtorosuccinimide, in a solvent selected from the group consisting of methanol, ethanol, acetonitrile, and dimethyl formamide at a temperature between 20° C and 40°C to produce (S)-3-(2-(chloroamino)-2-oxoethyl) hexanoic acid having the structure (III):

b) reacting (III) with sodium hydroxide in water, initially at a temperature between 15° C and 30°C, and later at a temperature between 85° C and 95° C to produce (R)-4-propyl-pyrrolidin-2-one having the structure (1)
(I) or optionally, the compound (III) is reacted with sodium hydroxide at a temperature between 15° C and 30°C to obtain (R)-3-(aminomethyl) hexanoic acid having the structure (IV)
followed by cyclizing the compound (IV) at a temperature between 85° C and 95° C to form (R)-4-propyl-pyrrolidin-2-one (I)
c) converting the reaction product of step (b) or (c) into brivaracetam.
2. A compound (S)-3-(2-(chloroamino)-2-oxoethyl) hexanoic acid having the structure (III)
3. The process as claimed in claim la, wherein the (S)-3-(2-amino-2-oxoethyl) hexanoic acid (II) is prepared by:
a) reacting 4-propyl piperidine-2,6-dione having the structure (V)

with an aqueous solution of sodium hydroxide at a temperature between 40° C and 60° C to obtain a racemic mixture of 3-(2-amino-2-oxoethyl) hexanoic acid having the structure (VI):
b) reacting racemic (VI) with (S)-(-)-l-PhenyIethylamine in chloroform containing (
2 to 5 % ethanol at a temperature between 40° C and 55° C followed by cooling to
obtain (S)-3-(2-amino-2-oxoethyl) hexanoic acid (II) as a salt of (S)-(-)-l-Phenylethylamine; and
c) hydrolyzing the precipitated salt to obtain (S)-3-(2-amino-2-oxoethyl) hexanoic
acid (II).
4. A process as claimed in claim 1, wherein the isomer, (R)-3-(2-amino-2-oxoethyl) hexanoic acid having the structure (Ha), remaining after obtaining (S)-3-(2-amino-2-oxoethyl) hexanoic acid (II) from the racemic mixture as per the reaction of claim 5 stage (b),

is heated in toluene in the presence of a catalyst selected from the group consisting of boron trioxide, para-toluenesulfonic acid and sulfuric acid at a temperature between 100°C and 110° C to obtain4-propyl piperidine-2,6-dione (V).