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with PPh3 progressed rapidly to completion in 60 min to
References and notes
give the desired 4-methoxyphenylacetonitrile, about 20%
of the product formed was the one carbon atom loss prod-
uct 4-methoxybenzonitrile.
To expand the applicability of this conversion to the
phenylacetonitrile, optimal experimental conditions,
including examination of other phosphorous reagents, were
developed.
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We postulated that the Curtius rearrangement would
more readily occur at higher temperatures, so the reaction
was performed at low temperature in hopes of favoring
formation of the acyl triazaphosphadiene, which further
cyclizes to an oxaphosphatriazine that loses N2 in a
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Using the optimized condition, the scope of this new
methodology was examined. As shown in Table 2, both
electron-poor and -rich phenylacetic acids were converted
to the corresponding phenylacetonitriles very efficiently
and in high yield (entries 1–7). Gratifyingly, we found that
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efficiently converted to their respective phenylacetonitriles
with these conditions.
In conclusion, we report the synthesis of benzonitriles
from the corresponding phenylacetic acids by a one carbon
atom loss process via Curtius rearrangement, deprotona-
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on the use of Deoxo-Fluor and sodium azide, which pre-
sumably convert the phenylacetic acid into an isocyanate
that is converted to the benzonitrile through a two-step
b-elimination process. Also, the reaction can be controlled
to give phenylacetonitriles by the inclusion of triethylphos-
phine in the reaction mixture. The ease, efficiency, and mild
conditions of this reaction make it an attractive alternative
to the existing methods.
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Acknowledgments
This investigation was supported by funding from the
National Institutes of Health of the University of Pitts-
burgh Obesity and Nutrition Research Center
(DK46204). We thank Professor Paul Floreancig for help-
ful discussions regarding the mechanism of the reaction.
Supplementary data
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Experimental procedures and spectroscopic data for the
new compounds. Supplementary data associated with this
article can be found, in the online version, at doi: