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described herein have led to new insights into the reaction
mechanism of the Sandmeyer cyclization reaction by mass
spectrometric characterization of its key reaction intermedi-
ates. The species 4, 9 and 10 have been transferred to the gas
phase, isolated by mass selection, and for the first time
detected and then structurally characterized by MS and
MS/MS experiments. The detection of 9 and 10 fully supports
the mechanism proposed for the Sandmeyer cyclization
reaction of isonitrosoacetanilide 3 to isatin 1 (Schemes 1
and 2). Nitrile species 5, and intermediates 6 and 7, were not
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n
suitability of coupling microreactors to ESI-MS techniques in
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phase, a vast but still under-explored field. This report is
another example of the successful application of atmospheric
pressure ionization (API) in revealing, elucidating, and
helping to consolidate previously proposed reaction mech-
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expected to find broad use in organic and organometallic
chemistry in probing many of their reaction and catalytic
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L.S.S. thanks FONDECYT (Project No. 1085308) for support of
research activity at Talca University. CAPES and CNPq are
acknowledged for financial support (B.V.S., F.A.V., A.C.P).
We thank Prof. Dr. Peter Bakuzis for further corrections in the
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