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A one-pot-three-step route to triazolotriazepinoindazolones from oxazolino-2H-indazoles.

ABSTRACT: A one-pot-three-step method has been developed for the conversion of oxazolino-2H-indazoles into triazolotriazepinoindazolones with three points of diversity. Step one of this process involves a propargyl bromide-initiated ring opening of the oxazolino-2H-indazole (available by the Davis-Beirut reaction) to give an N(1)-(propargyl)-N(2)-(2-bromoethyl)-disubstituted indazolone, which then undergoes -CH(2)Br ? -CH(2)N(3) displacement (step two) followed by an uncatalyzed intramolecular azide-alkyne 1,3-dipolar cycloaddition (step three) to form the target heterocycle. Employing 7-bromooxazolino-2H-indazole allows for further diversification through, for example, palladium-catalyzed coupling chemistry, as reported here.

SUBMITTER: Conrad WE

PROVIDER: S-EPMC3427757 | biostudies-literature | 2012 Aug

REPOSITORIES: biostudies-literature

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A one-pot-three-step route to triazolotriazepinoindazolones from oxazolino-2H-indazoles.

Conrad Wayne E WE Rodriguez Kevin X KX Nguyen Huy H HH Fettinger James C JC Haddadin Makhluf J MJ Kurth Mark J MJ

Organic letters 20120723 15

A one-pot-three-step method has been developed for the conversion of oxazolino-2H-indazoles into triazolotriazepinoindazolones with three points of diversity. Step one of this process involves a propargyl bromide-initiated ring opening of the oxazolino-2H-indazole (available by the Davis-Beirut reaction) to give an N(1)-(propargyl)-N(2)-(2-bromoethyl)-disubstituted indazolone, which then undergoes -CH(2)Br → -CH(2)N(3) displacement (step two) followed by an uncatalyzed intramolecular azide-alkyn ...[more]

PMID: 22823414

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