Synthesis of N-Alkyl-1,3-dihydro-2,1-benzisoxazoles
Thomas D Beckler1,2, David Crich1,2,3
1Department of Chemistry, University of Georgia, Athens, Georgia 30602, United States.
Abstract:
We describe a practical method for the synthesis of various substituted N-alkyl-1,3-dihydro-2,1-benzisoxazoles and their 2,1-benzisoxazolone precursors starting from readily available methyl 2-nitrobenzoates. The method entails partial nitro reduction with hydrazine and rhodium on carbon to give the hydroxylamines, followed by base-mediated cyclization to give the corresponding benzisoxazol-3(1H)-ones. Subsequent alkylation is conducted under basic conditions and is followed by reduction to the target 1,3-dihydrobenzisoxazoles, achieved with lithium aluminum hydride in the presence of trimethylsilyl chloride.
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