67118-31-4Relevant articles and documents
Preparation method of levetiracetam and intermediates thereof
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Paragraph 0043-0045; 0047, (2020/01/08)
The invention provides a preparation method of levetiracetam and intermediates thereof. The specific steps are as follows: dropwise adding pyrrolidone into a toluene solution of sodium methoxide or sodium hydride, performing concentrating to dryness after a reaction is completed, adding toluene again, dropwise adding ethyl 2-bromobutyrate, and carrying out a reaction by heating to obtain a compound of a formula 3; adding a NaOH aqueous solution to the compound of the formula 3, performing heating until a reaction is completed, and dropwise adding concentrated hydrochloric acid to precipitate acompound of a formula 4; carrying out a reaction of the compound of the formula 4, R-(+)-phenylethylamine, and triethylamine to obtain a compound of a formula 6; performing hydrolysis by a NaOH solution, acidification by concentrated hydrochloric acid, and purification to a compound of a formula 7; and performing esterification by TsOH/EtOH to obtain a compound of a formula 8, and then performingammonia hydrolysis to obtain levetiracetam.