South. Braz. J. Chem. (2009), 17(17), 1-5

    ISSN 0104-5431

CODEN   SBJCEO

     Indexed in Chemical Abstract:

An efficient synthesis of b-(3-quinolinyl)-a-alanine

    STEFAN H. ÖHLINGER

Abstract:

A convenient synthesis for b-(3-quinolinyl)-a-alanine (4) is presented. Condensation of 2-chloro-3-chloromethylquinoline (5) with diethyl acetamidomalonate (2) gave high yield of diethyl 2-acetylamino-2-(2-chloro-3-quinolinylmethyl)-propanedionate (6), which was dehalogenated in the presence of ammonium formate and palladium/charcoal. Diethyl 2-acetamido-2-(3-quinolinylmethyl)-malonate (3) was easily converted to the amino acid. The condensation reaction between 2 and 6 is also useful for the construction of (1H)-2,3-dihydropyrrolo[2,3-b]quinoline-2,2-bis(carboxylic acid) and pyrrolo[2,3-b]quinoline-2-carboxylic acid derivatives.

Keywords: reductive dehalogenation; unnatural amino acid; b-(3-quinolinyl)-a-alanine; pyrrolo[2,3-b]quinoline-2-carboxylic acid skeleton

Resumo:

Uma síntese eficaz para b-(3-quinolinil)-a-alanina (4) é apresentada. A condensação de 2-cloro-3-clorometilquinolina (5) com dietilacetamido malonato (2) levou a um rendimento alto de dietil 2-acetilamino-2-(2-cloro-3-quinolinilmetil)-propanodionato (6), que foi sujeito à dehalogenação na presença de Pd/C. O dietil 2-acetamido-2-(3-quinolinilmetil)-malonato (3) foi facilmente convertido no amino ácido. A reação de condensação entre 2 e 6 é também útil para a síntese de (1H)-2,3-dihidropirolo[2,3-b]quinolina-2,2-bis(ácido carboxílico) e derivados de pirolo[2,3-b]quinolina-2-ácido carboxílico.

Palavras chaves: dehalogenação redutiva; amino ácido não-natural; b-(3-quinolinil)-a-alanina; esqueleto de pirolo[2,3-b]quinolina-2-ácido carboxílico

CAS Registry Number for (Acetylamino)(3-quinolinylmethyl)-propanedionic acid diethylester (3): [120652-19-9]

CAS Registry Number for a-amino-3-quinolinepropanoic acid (4): [1954-41-2], (±)-[26988-99-8]

CAS Registry Number for 2-chloro-3-(chloromethyl)-quinoline (5): [90097-52-2]

CAS Registry Number for a-amino-1,2-dihydro-2-oxo-3-quinolinepropanoic acid (9): [90098-97-8]

CAS Registry Number for a-amino-1,2-dihydro-2-oxo-3-quinolinepropanoic acid, hydrochloride (9-HCl): [90098-49-0]