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R
N
References and notes
R
O
N
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O
TMS
Cl
Cl
N
NH
TMS
N
N
HN
R1
N
R1
4a-c
- ClCN
R
O
TMS
N
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5a-c
Figure 3. Proposed Diels–Alder reaction mechanism.
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quadrupole system equipped with electrospray ionization (ESI) source, UV
detector (220 and 254 nm), and evaporative light-scattering detector (ELSD).
Data are reported for HPLC product peak integration ratios at 254 nm.
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od allows for a high degree of diversity at the 5- and 8-positions of
the tricyclic core. These results provide new possibilities for utiliz-
ing the 7-aza-a-carboline system in drug discovery.
Supplementary data
Supplementary data (chemistry experimental procedures and
compound characterization) associated with this article can be