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Acid and base catalyzed Davis-Beirut reaction: experimental and theoretical mechanistic studies and synthesis of novel 3-amino-2H-indazoles.

ABSTRACT: The Davis-Beirut reaction, which provides an efficient synthesis of 2H-indazoles and, subsequently, indazolones, is shown to proceed rapidly from o-nitrosobenzaldehyde and primary amines under both acid or base catalysis. Experimental and theoretical evidence in support of a reaction mechanism is provided in which o-nitrosobenzylidine imine is a pivotal intermediate in this N,N-bond forming heterocyclization reaction. The Davis-Beirut reaction is also shown to effectively synthesize a number of novel 3-amino-2H-indazole derivatives.

SUBMITTER: Avila B

PROVIDER: S-EPMC3489190 | biostudies-literature | 2012 Nov

REPOSITORIES: biostudies-literature

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Acid and base catalyzed Davis-Beirut reaction: experimental and theoretical mechanistic studies and synthesis of novel 3-amino-2H-indazoles.

Avila Belem B El-Dakdouki Mohammad H MH Nazer Musa Z MZ Harrison Jason G JG Tantillo Dean J DJ Haddadin Makhluf J MJ Kurth Mark J MJ

Tetrahedron letters 20120915 48

The Davis-Beirut reaction, which provides an efficient synthesis of 2H-indazoles and, subsequently, indazolones, is shown to proceed rapidly from o-nitrosobenzaldehyde and primary amines under both acid or base catalysis. Experimental and theoretical evidence in support of a reaction mechanism is provided in which o-nitrosobenzylidine imine is a pivotal intermediate in this N,N-bond forming heterocyclization reaction. The Davis-Beirut reaction is also shown to effectively synthesize a number of ...[more]

PMID: 23139435

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Davis-Beirut reaction: route to thiazolo-, thiazino-, and thiazepino-2H-indazoles.

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