- Efficient synthesis of β-aryl-γ-lactams and their resolution with (S)-Naproxen: Preparation of (R)- and (S)-Baclofen
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An efficient synthesis of enantiomerically-pure β-aryl-γ-lactams is described. The principal feature of this synthesis is the practical resolution of β-aryl-γ-lactams with (S)-Naproxen. The procedure is based on the Michael addition of nitromethane to benzylidenemalonates, which was easily obtained, followed by the reduction of the γ-nitroester in the presence of Raney nickel and the subsequent saponification/decarboxylation reaction. The utility of this methodology was highlighted by the preparation of enantiomerically-pure (R)- and (S)-Baclofen hydrochloride.
- Montoya-Balbás, Iris J.,Valentín-Guevara, Berenice,López-Mendoza, Estefanía,Linzaga-Elizalde, Irma,Ordo?ez, Mario,Román-Bravo, Perla
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p. 22028 - 22043
(2016/01/25)
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- Process for producing β-phenyl-γ-amino butyric acid hydrochloride
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The invention relates to a new substance, namely the hydrochloride of β-phenyl- γ-aminobutyric acid of the following formula: EQU1 and to the process for its production which comprises condensing malonic ester with β-nitrostyrene resulting in the separation of an ester of γ-carbomethoxy-β-phenyl-γ-nitrobutyric acid at a temperature ranging from 0° to 14°C, reducing the ester thus obtained with hydrogen in the presence of the Raney nickel under a pressure of 6 to 30 atm, treating 3-carbomethoxy-4-phenyl-2-pyrrolidone, as formed by the reduction, with hydrochloric acid, and separating the desired product.
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