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US 7,923,575 B2Granted
Asymmetric synthesis of (S)-(+)-3-(aminomethyl)-5-methylhexanoic acid
AssigneeTeva Pharmaceutical Industries Ltd.
InventorsVinod Kumar Kansal, Brijnath P. Chaurasia, V. Govardhan Rao, Anand Prakash Tiwari
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Abstract
The invention encompasses processes for the synthesis of (S)-(+)-3-(aminomethyl)-5-methylhexanoic acid, (S)-Pregabalin, and intermediates of (S)-Pregabalin.
Claims32
A process for preparing (S)-Pregabalin:
- comprising:
- a) preparing a compound of the following formula 24:
- wherein Ar is a C6-10 aromatic group and R is a straight or branched C1-4 alkyl, ester, or carboxylic acid;
- b) reacting the compound of formula 24 with an amidation reagent to produce a compound of the following formula 25:
- wherein Ar is a C6-10 aromatic group, and R is a straight or branched C1-4 alkyl, ester, or carboxylic acid;
- c) carrying out a Hoffman reaction on the compound of formula 25 to produce a compound of the following formula 26:
- wherein Ar is a C6-10 aromatic group, and R is a straight or branched C1-4 alkyl, ester, or carboxylic acid;
- d) reacting the compound of formula 26 with ammonia and an alkali metal to produce a compound of the following formula 27;
- wherein R′ is a straight or branched C1-5 alkyl;
- and
- e) reacting the compound of formula 27 with an acid to produce (S)-Pregabalin.
8 more elements
Dependencies are inferred from the claim text.