RESUMO
Under conventional heat (135-145 degrees C) or microwave irradiation and 1 equiv of acetic anhydride, ortho-substituted aryl-oximes undergo a novel sp3 C-H activated cyclization to produce the corresponding isoindoles, and aliphatic oximes afford the corresponding dihydropyrroles. The cyclization occurs with various substrates in good yield (46-82%) leading to unique spiro-fused and cyclic imines. An initial mechanistic investigation suggests the reaction occurs via a nitrenium or vinyl nitrene intermediate. [reaction: see text]
Assuntos
Técnicas de Química Combinatória , Iminas/síntese química , Oximas/química , Compostos de Espiro/síntese química , Anidridos Acéticos/química , Ciclização , Temperatura Alta , Iminas/química , Indóis/química , Micro-Ondas , Modelos Químicos , Pirróis/química , Compostos de Vinila/químicaRESUMO
We report the first case of a pharmaceutical cocrystal formed between an inorganic acid and an active pharmaceutical ingredient (API), which enabled us to develop a stable crystalline and bioavailable solid dosage form for pharmaceutical development where otherwise only unstable amorphous free form or salts could have been used.
Assuntos
Fosfatos/química , Ácidos Fosfóricos/química , Cristalização , Espectroscopia de Ressonância Magnética , Modelos Moleculares , Estrutura Molecular , Fosfatos/farmacologiaRESUMO
An improved protocol for N-acetyl enamine formation is disclosed which involves LiBr-mediated addition of MeLi to substituted nitriles. The resulting enamides are isolated in high yields and excellent purity which permits subsequent hydrogenation at very low catalyst loading.
RESUMO
[reaction: see text] We describe herein a new base-mediated process for the formation of N-arylpyridinones 2 and their use for the preparation of naphthyridones and quinolines. The cyclization of various hindered enamines with methyl propiolate proceeds efficiently in the presence of NaOH to afford the corresponding N-arylpyridinones. These substrates were then found to undergo subsequent cyclizations to afford highly functionalized naphthyridones and quinolines.