Synthesis and evaluation of 7,8-dehydrorutaecarpine derivatives as potential multifunctional agents for the treatment of Alzheimer's disease

Article abstract of DOI:10.1016/j.ejmech.2013.02.014

A series of 7,8-dehydrorutaecarpine derivatives were synthesized and characterized as potential multifunctional agents for treatment of Alzheimer's disease (AD). All of these synthetic compounds showed high acetylcholinesterase (AChE) inhibitory activity with IC₅₀ values ranged from 0.60 to 196.7 nM, and good selectivity for AChE over butyrylcholinesterase (BuChE) (125- to 3225-fold). A Lineweaver-Burk plot and molecular modeling study indicated these compounds could bind to both catalytic active site and the peripheral anionic site of AChE. Besides, compounds showed higher activity of inhibiting AChE-induced amyloid-beta (Aβ) aggregation than curcumin, higher anti-oxidative activity than Trolox, and could also be good metal chelators. Considering their low cytotoxicity, our results indicated that these derivatives provide good templates for developing new multifunctional agents for AD treatment.

Full text of DOI:10.1016/j.ejmech.2013.02.014

Accepted Manuscript
Synthesis and evaluation of 7,8-dehydrorutaecarpine derivatives as potential
multifunctional agents for the treatment of Alzheimer’s disease
Yan He, Pei-Fen Yao, Shuo-bin Chen, Zhi-hong Huang, Shi-Liang Huang, Jia-Heng
Tan, Ding Li, Lian-Quan Gu, Zhi-Shu Huang
PII:
S0223-5234(13)00108-6
10.1016/j.ejmech.2013.02.014
EJMECH 6004
DOI:
Reference:
To appear in: European Journal of Medicinal Chemistry
Received Date: 14 December 2012
Revised Date: 31 January 2013
Accepted Date: 13 February 2013
Please cite this article as: Y. He, P.-F. Yao, S.-b. Chen, Z.-h. Huang, S.-L. Huang, J.-H. Tan, D. Li,
L.-Q. Gu, Z.-S. Huang, Synthesis and evaluation of 7,8-dehydrorutaecarpine derivatives as potential
multifunctional agents for the treatment of Alzheimer’s disease, European Journal of Medicinal
Chemistry (2013), doi: 10.1016/j.ejmech.2013.02.014.
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ACCEPTED MANUSCRIPT
Synthesis and evaluation of 7,8-dehydrorutaecarpine derivatives as potential multifunctional
agents for the treatment of Alzheimer’s disease
Yan He, Pei-Fen Yao, Shuo-bin Chen, Zhi-hong Huang, Shi-Liang Huang, Jia-Heng Tan, Ding Li, Lian-Quan Gu,
Zhi-Shu Huang*
Twenty seven new 3-aminoalkanamido-substituted 7,8-dehydrorutaecarpine derivatives were synthesized as
multifunctional anti-Alzheimer agents, these compounds showed activities of cholinesterase inhibition, self and
AChE-induced Aβ aggregation inhibition, antioxidation, and metal chelation.

ACCEPTED MANUSCRIPT
Title Page
Synthesis and evaluation of 7,8-dehydrorutaecarpine derivatives as potential multifunctional
agents for the treatment of Alzheimer’s disease
Yan He, Pei-Fen Yao, Shuo-bin Chen, Zhi-hong Huang, Shi-Liang Huang, Jia-Heng Tan, Ding Li, Lian-Quan Gu,
Zhi-Shu Huang*
School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, People’s Republic of China
*To whom correspondence should be addressed. Tel.: 8620-39949056, Fax.: 8620-39943056, e-mail:
ceshzs@mail.sysu.edu.cn.
Abstract
A series of 7,8-dehydrorutaecarpine derivatives were synthesized and characterized as potential
multifunctional agents for treatment of Alzheimer’s disease (AD). All of these synthetic compounds showed
high acetylcholinesterase (AChE) inhibitory activity with IC values ranged from 0.60 to 196.7 nM, and good
50
selectivity for AChE over butyrylcholinesterase (BuChE) (125- to 3225-fold). A Lineweaver-Burk plot and
molecular modeling study indicated these compounds could bind to both catalytic active site and the
peripheral anionic site of AChE. Besides, compounds showed higher activity of inhibiting AChE-induced
amyloid-beta (Aβ) aggregation than curcumin, higher anti-oxidative activity than Trolox, and could also be
good metal chelators. Considering their low cytotoxicity, our results indicated that these derivatives provide
good templates for developing new multifunctional agents for AD treatment.
Keywords:
7,8-dehydrorutaecarpine derivatives
Alzheimer’s disease
Acetylcholinesterase
Aβ aggregation
Antioxidant
Metal-chelating
Abbreviations:
AD: Alzheimer’s disease
AChE: acetylcholinesterase
BuChE: butyrylcholinesterases
Aβ: amyloid β-peptide
PAS: peripheral anionic site
CAS: catalytic active site
MTT: methyl thiazolyl tetrazolium
ORAC: oxygen radical absorbance capacity
ThT: thioflavin T
1

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1
. Introduction
Alzheimer’s disease (AD) is clinically characterized by a progressive and irreversible cognitive impairments
and memory loss [1]. The treatment for AD remains a challenge for pharmaceutical scientist. Although the
pathogenesis of AD is not completely known, several factors, such as cholinergic hypothesis, amyloid-beta
(
Aβ) aggregation, tau hyperphosphorylation, and oxidative stress have been considered to play definitive roles
in its etiology [2]. The treatment with acetylcholinesterase inhibitors (AChEIs), such as donepezil,
rivastigmine, and galantamine, based on so-called cholinergic hypothesis, has been used as therapeutic
approach for AD treatment [3]. However, the functions of butyrylcholinesterase (BuChE), another type of
cholinesterase, which is mainly abundant outside human brain, are still unclear. Several studies have
suggested that inhibition of BuChE may contribute to the peripheral side effects of cholinesterase inhibitors
[
4], like the dual AChE and BuChE inhibitors tacrine, which showed serious hepatotoxicity and other side
effects [5]. In addition, it has been recently reported that in vivo BuChE activity is not increased in
Alzheimer's disease synapses of patients [6]. Therefore, it may be a good approach to develop specific AChE
inhibitors for the treatment of AD, with expectation for their fewer side effects.
The progressive aggregation and deposition of Aβ, one of the major neuropathological features in AD patients,
is considered to be crucial to the pathology [7]. In particular, Aβ1−42 is the predominant form in amyloid
plaques, revealing lower solubility and stronger neuronal toxicity than Aβ1−40 [8]. Preventing the formation
and aggregation of Aβ is a potential method for AD treatment [9]. In order to achieve this purpose, several
series of inhibitors were being pursued, such as curcumin, Congo-red, benzofuran, acridone and rifampicin
derivatives or analogues [10, 11], to disrupt the process of Aβ fibrillization. Recent molecular dynamics
simulation studies revealed that aromatic residues of Aβ played a crucial role in the formation and
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stabilization of polymeric structures [12-14]. Several polyphenols and other small aromatic molecules were
displayed to inhibit the amyloid aggregation [15, 16]. Besides, the strategy of designing peptide-based
inhibitors which can interrupt the β-sheet structure of the amyloid core or can form complexes with the helical
elements in the primary structure of the amyloidogenic peptide to prevent the formation of amyloid structures
is effective [17-19]. On the other hand, recent studies have reported the ability of purified AChE to promote
the assembly of Aβ peptide into amyloid fibril, which was so-called AChE-induced Aβ aggregation. There is
evidence that AChE can bind to the Aβ non-amyloidogenic form, forming with them stable complexes by
means of a protein-protein interaction, enhancing the aggregation of Aβ fragments and accelerating the
conformational transition into amyloid fibrils and senile plaques [20]. The aggregation-promoting action
seems to be associated with a structural domain, located close to the entrance of the AChE active-site gorge,
perhaps overlapping the peripheral anionic site (PAS) of AChE other than the active center [21, 22]. Thus,
inhibiting the PAS of AChE can affect the AChE-induced Aβ aggregation [21-23]. On this premise, novel
classes of AChE inhibitors targeting PAS have emerged as promising anti-Alzheimer drug candidates [24].
During aging, the progressive damage of the endogenous antioxidant protection system is another obvious
phenomenon in AD. Moreover, increasing evidence supports the significant impact of oxidative stress in the
pathogenesis and progression of AD [25, 26]. Recent studies have indicated that oxidative damage could
promote the appearance of amyloid plaques and neurofibrillar tangles in AD [27]. Thus, drugs that aimed at
clearing or preventing the formation of the free radicals could be useful for AD treatment. It has been
2
+
2+
suggested redox-active metal ions like Cu and Fe might contribute to the production of reactive oxygen
species (ROS) and oxidative stress [28]. Therefore, metal chelators, such as desferrioxamine [29], clioquinol
(
CQ) [30], and 8-hydroxyquinoline derivative (PBT2) [31] have been proposed as potential therapeutic
3

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substances for the treatment of AD [32].
The development of multifunctional agents with two or more correlative biological activities, corresponding
with the multi-factors causing AD, has drawn most attention for their important advance in the treatment of
AD [33], while it remains a difficult task. Selecting a promising lead compound becomes the key point to
explore potential multifunctional drugs. We have previously studied a series of rutaecarpine derivatives as
selective AChE inhibitors, and found that the compounds with 7,8-dehydrorutaecarpine (DHRu, Fig.1) moiety
had better potency than that of derivatives with rutaecarpine (Ru, Fig.1) moiety [34]. Moreover, it has been
reported that carbazole derivatives have the capacity of inhibiting Aβ aggregation [35] with
free-radical-scavenging effect [36]. Thus, we are interested in the development of novel
7,8-dehydrorutaecarpine derivatives as potential multifunctional agents for the treatment of Alzheimer’s
disease. In the present study, a series of new 3-aminoalkanamido-substituted 7,8-dehydrorutaecarpine
derivatives (Fig.1) were designed, synthesized, and evaluated for their biological activity, including inhibition
of cholinesterase, inhibitory effects on self and AChE-induced Aβ aggregation, anti-oxidative activity, and
metal chelating property.
2
. Chemistry
The synthetic pathway for 3-aminoalkanamido-substituted 7,8-dehydrorutaecarpine derivatives 9a∼ 9l,
0a∼ 10n, 11a, 11c, 11f and 11l is shown in Scheme 1. Compounds 9e, 9f and 9g have been reported in our
1
previous work [34]. The synthetic methodology for the key intermediate 3-amino-rutaecarpine (6) followed
the Bergman pathway with minor modification [37], as shown in Scheme 2. Firstly, reaction of the nitro
isatoic anhydride with tryptamine under reflux for 2h in pyridine containing trifluoroacetic anhydride gave 3
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in 50% yields. Then, compound 3 was cyclized to 4 in HCl-AcOH conditions under reflux for 1h in 95%
overall yield. The compound 4 was hydrogenated in the catalysis of 10% Pd/C, yielding the compound 5.
Lastly, the treatment of 5 with alcoholic KOH eliminated the fluoroform group, providing the compound 6 in
99% yields.
The preparation for intermediates 7a∼ 7c was accomplished by the acylation of 6 with appropriate acyl
chloride, following a previously reported procedure [34]. The treatment of compounds 7a∼ 7c with DDQ in
dioxane under reflux for 12h gave the dehydrogenated 8a∼ 8c. Finally, the lead compounds 9a∼ 9k, 10a∼ 10k,
11a, 11c and 11f were obtained from 8a∼ 8c in the presence of appropriate amines under reflux for 8h. The
preparation for intermediates 12a∼ 12c was accomplished by the condensation reaction of 6 with appropriate
aromatic acid, followed by the dehydrogenation with DDQ, giving the lead compounds 9l, 10l and 11l. In
addition, the methylation of compounds 10d and 10f with iodomethane in thiocyclopentane produced the lead
1
compounds 10m and 10n (Scheme 1). The structures of the lead compounds were validated by using H NMR,
13
C NMR, and HRMS, and their purities were determined to be above 95% by using HPLC.
3
. Results and Discussion
3
.1 Inhibition studies on AChE and BuChE
The inhibitory activity of our synthetic derivatives was evaluated against AChE and BuChE using the method
of Ellman et al. [38] with tacrine as a positive control. Their IC50 values and selectivity index for the inhibition
of AChE and BuChE are summarized in Table 1. All these compounds were tested in five concentrations
limited up to 100 µM, resulting in ranged from 20% to 80% enzyme inhibition. For comparison, tacrine and
previously reported compounds 9e∼ 9g were tested under the same experimental conditions. As shown in
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Table 1, all synthetic derivatives showed high inhibitory activity and good inhibition selectivity against AChE
over BuChE. Compounds 9a and 9b displayed the most potent inhibitory activity and inhibition selectivity for
AChE, with their IC50 values of 0.76 nM and 0.60 nM, and selectivity indexes of 3225 and 3092, respectively.
Comparing with the positive control and previously synthesized compounds 9e∼ 9g, the inhibitory activity of
compounds 9a and 9b was 160−180-fold better than tacrine, and 100−120-fold better than 9e∼ 9g.
Simultaneously, their inhibition selectivity for AChE increased about 10-fold compared with compounds
9e∼ 9g (Table 1). To investigate whether the improvement was due to the N-heteroaromatic ring or the positive
charge, we designed and synthesized derivatives 10m and 10n with the aliphatic ring or alkyl quaternary
ammonium at the end of side chain. The result showed a 2~3 times decrease in activity for 10m and 10n
comparing with the corresponding compounds without positive charges, 10d and 10f. It indicated that the
terminal N-heteroaromatic ring played an important role in enhancing their inhibitory potency and selectivity
against AChE. And it also might be the reason why our novel compounds have higher activity and selectivity
for AChE than those reported before [34]. In order to further confirm the role of N-heteroaromatic ring, we
also synthesized several derivatives with phenyl or pyridyl group at the end of side chain, including
compounds 9j~9l, 10j~10l, and 11l, it was found that compounds (9j and 10j) with pyridyl group had better
activity than those with phenyl group. This result told us that the electron density of aromatic ring might be
associated with the inhibitory activity.
On the other hand, we also investigated the effects of the side chain length on inhibitory ability of AChE. As
shown in Table 1, two series of compounds (9a∼ 9i, 9l and 10a∼ 10i, 10l), which had a linkage of one or two
atoms (n = 1 or n = 2) in side chain respectively, did not show significant difference in their inhibitory activity.
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But when the side chain length was further increased to three atoms, it showed a decrease on inhibitory
activity. For example, compared with 9a and 10a (IC50 for AChE, 0.8 nM and 2.3 nM respectively), the
activity of 11a (IC50 for AChE, 3.9 nM) with a linker of three methylene groups had about 20-fold and
1.7-fold decrease, respectively. And the activities of other compounds 10j∼ 10k, 11c, 11f, and 11l were also
correspondingly lower than those of compounds 9j∼ 9k, 10c, 10f, and 10l. Therefore, the linkage with 1 to 2
atoms seems to be in favor of inhibition for AChE.
3
.2 Kinetic studies for the inhibition of AChE
Compounds 9b and 10f with different structures (with or without a positive charge) had the best inhibitory
activity for AChE, which were further studied by graphical analysis of their steady-state inhibition data, as
shown in Figure 2. The Lineweaver-Burk plots showed that both inhibitions had rising slopes and increasing
intercepts at higher inhibitor concentration, which indicated a mixed-type inhibition. It was shown that
compounds 9b and 10f could bind to both catalytic active site (CAS) and PAS of AChE, which are similar to
that of tacrine and consistent with our results of molecular modeling study.
3
.3 Molecular modeling study
To investigate the interacting mode between our synthetic compounds and TcAChE (PDB code: 1ACJ), a
molecular modeling study utilizing the docking program named AUTODOCK 4.0 package with Discovery
Studio 2.5 was carried out [39, 40]. The results of docking showed that our synthetic compounds displayed
multiple binding patterns with TcAChE, as shown in Figure 3A. In the TcAChE-9b complex, the
7,8-dehydrorutaecarpine moiety occupied the PAS of enzyme and possessed potential hydrophobic interaction
with residues Tyr334, Phe330, Phe290 and Tyr121. Moreover, it might induce π–π interactions with these
7

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residues when the bond of these residues rotated. The linker was long enough for the pyridyl substituted group
arriving in the CAS of AChE, causing potential π–cation interaction and hydrophobic interaction with residues
Trp84 and Tyr130. But the compounds with a too long linker (3 atoms) will result in the overcrowding of
CAS domain and change the binding mode of whole molecule. The results of docking explained why the
compounds with terminal N-heteroaromatic ring in the side chain and appropriate length of linker have higher
inhibition potency against AChE, and were consistent with results of structure-activity relationship of our
synthesized compounds for AChE mentioned above. The simultaneously binding of 9b with the peripheral site
and active gorge of TcAChE explained the promising potency for AChE inhibition and revealed a mixed-type
inhibition of compound. In addition, we also performed a docking between 9b and HuBuChE (PDB code:
1POI) using same program. As shown in Figure 3B, it was found that the 7,8-dehydrorutaecarpine moiety
entered the catalytic active site of BuChE and interact with residue Asp200. No other notably interaction was
observed between 9b and HuBuChE, giving the reason for weaker inhibition of compounds on BuChE and
higher selectivity for AChE.
3
.4 Inhibition of self and AChE-induced Aβ(1−42) aggregation
The inhibition of self and AChE-induced amyloid-beta (1−42) (Aβ1−42) aggregation by our synthetic
derivatives was determined by using thioflavin T (ThT) assay [41], with tacrine, curcumin, propidium iodide
and Congo-red as reference compounds. Table 2 and Figure 4 summarized the data for their effects on Aβ1−42
peptide aggregation at concentration of 25 µM. In the ThT assay screening for Aβ1−42 peptide self-aggregation
inhibition, the most potent compounds were found to be 10a∼ 10b, 11a and 11c with respective inhibition ratio
of 61%, 54%, 60% and 55%, which are higher than that of curcumin (51%). The activities of other compounds
are similar or lower than that of curcumin. To further explore the dual effects of these compounds,
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AChE-induced Aβ1−42 aggregation inhibitory activity was examined based on the same ThT assay. Aβ
deposition in AD brain has been linked to AChE expression, and the PAS of AChE can bind to the Aβ,
accelerating the formation of amyloid fibrils [20]. Thus, inhibition of AChE, especially inhibition of PAS of
AChE, might affect Aβ aggregation. As shown in Table 2 and Figure 4, tacrine, which had higher affinity for
CAS than for PAS of AChE, showed a small effect (about 5% at 25 µM) against AChE-induced Aβ1−42
aggregation. However, propidium iodide significantly reduced Aβ1−42 aggregation (about 85%) as a result of
its noncompetitive inhibition type. Remarkably, all of our synthetic derivatives showed good inhibitory
potency against AChE-induced Aβ1−42 aggregation ranging from 75.9% to 92.8%, being 15.3- to 18.6-fold
more effective than tacrine and 2.2- to 2.7-fold more effective than curcumin. Besides, compounds 9a∼ 9c, 9j,
1
0a∼ 10c, 11a and 11c showed higher inhibitory activity against AChE-induced Aβ1−42 aggregation than
propidium iodide and our previous compounds 9e∼ 9g, with inhibition ratio of 92.8%, 90.6%, 90.0%, 87.9%,
0.3%, 89.6%, 87.0%, 90.1% and 88.4%, respectively. Interestingly, this result is consistent with the outcome
9
of inhibition against AChE and the previous study that the pyridinium-type compounds have shown high dual
inhibitory potency against AChE and Aβ aggregation [42].
3
.5 Studies of antioxidative activity
The reduction of the oxidative stress is another crucial aspect in designing agents for AD treatment. We
examined the antioxidative activities of part of our synthetic derivatives and the oxygen radical absorbance
capacity (ORAC) method was used. Their ability to scavenge radicals was shown as Trolox (a vitamin E
analogue) equivalent, with their relative potency at concentration of 1 and 5 µM compared to that of Trolox
(
shown in Table 2). The data showed that all the tested derivatives had better antioxidative activity ranging
from 1.5- to 3.9-fold of Trolox, as a result for the introduction of the carbazole moiety to the backbone, giving
9

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high antioxidative potency [36]. Furthermore, compounds 9d∼ 9i and 10d∼ 10i showed higher antioxidative
activities than compounds 9a∼ 9c, 10a∼ 10c and 10m∼ 10n. It indicated that the positive charge of side chain
may weaken the antioxidative activity of compounds, and aliphatic side chains are more important than
aromatic side chains for enhancing their antioxidative activity.
3
.6 Studies of metal-chelating properties
+
+
2+
2+
2+
2+
The chelation activity of the most potent compound 9b for biometals such as Na , K , Mg , Ca , Cu , Fe ,
2
+
and Zn was studied by using UV-vis spectrometry. The UV absorption of compound 9b in ethanol changed
2
+
2+
2+
+
+
2+
2+
with the titration of Cu , Fe and Zn , while litter change occurred after titrating with Na , K , Mg , Ca .
The maximum change in absorption intensity can be observed after adding CuSO , followed by ZnSO and
4
4
4
FeSO (shown in Fig. 5A), indicating the formation of complex 9b-metal (II). The molar ratio method was
performed to determine the stoichiometry of the complex 9b-metal (II) by titrating the ethanol solution of
compound 9b with ascending amounts of CuSO4 [43]. The UV spectra were recorded and treated by
numerical subtraction of CuSO and 9b at corresponding concentrations, plotted versus the mole fraction of
4
9b. As shown in Figure 5B, the absorption firstly increased at 416 nm and then reached saturation point versus
2+
the mole proportion of Cu to 9b. The point for the two straight lines to intersect was determined to be at the
mole proportion of 1.04, indicating 1:1 stoichiometry of the ligand-metal (II) complexes.
3
.7 Studies of cytotoxic effects on SH-SY5Y
To determine the potential cytotoxic effects of our synthetic derivatives, the human neuroblastoma cell line
SH-SY5Y was treated with part of our lead compounds at 0.1, 1.0, 10, and 100 µM for 48h. The cell viability
was calculated by using MTT colorimetry. As shown in Table 2, compounds 9a∼ 9c and 10a∼ 10c with higher
10

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inhibitory activity on AChE and AChE-induced Aβ1−42 aggregation showed negligible cell death and higher
IC50 values (above 100 µM) than that of curcumin (38 µM) under the same experimental conditions,
indicating their lower neural cytotoxic effects.
4
. Conclusion
In summary, twenty seven new 3-aminoalkanamido-substituted 7,8-dehydrorutaecarpine derivatives 9a∼ 9d,
h∼ 9l, 10a∼ 10n, 11a, 11c, 11f and 11l were synthesized and characterized as multifunctional anti-Alzheimer
9
agents. All of these synthetic compounds showed high AChE inhibitory potency and good selectivity for
AChE over BuChE. Structure-activity relationship analysis showed that the introduction of N-heteroaromatic
ring at the end of their side chain was crucial to their inhibitory potency and selectivity against AChE. For
example, the most potent compounds 9a∼ 9c, 9j, 10a∼ 10c, 11a and 11c possessed better inhibitory activity
(
IC50 for AChE, 0.6∼ 11.7 nM) and higher inhibition selectivity for AChE (Selectivity index ranged from 701
to 3225) than those of compounds with phenylic or aliphatic side chains. Moreover, the positive charge of side
chains perhaps had little effect on their inhibitory activity and selectivity for AChE according to 9j (3.9 nM)
and 10a (2.3 nM) having similar inhibitory activity for AChE. It showed a decrease on inhibitory activity with
increasing side chain length to a linkage of 3 atoms and indicated that the linker with 1 or 2 atoms was in
favor of inhibition for AChE. Both the inhibition kinetic analysis and molecular modeling study suggested that
representative compounds 9b and 10f showed mixed-type inhibition, which figured out that compounds could
bind to both CAS and PAS of AChE, inducing strong inhibitory effect and selectivity for AChE. In addition,
all these lead compounds showed high effective activity of inhibiting AChE-induced Aβ1−42 aggregation than
curcumin, especially compounds 9a∼ 9c, 9j, 10a∼ 10c, 11a and 11c (ranged from 2.5- to 2.7-fold of curcumin).
This result is consistent with the outcome for their inhibition against AChE. Furthermore, these lead
11

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compounds could be metal chelators with better antioxidative property than Trolox due to the carbazole
moiety of backbone and the introduction of side chain. The positive charge of side chain may weaken their
antioxidative activity, and aliphatic side chains are more important than aromatic side chains for their
antioxidative activity. Considering their low cytotoxicity, our results indicate that our new compounds provide
good templates for development of new multi-functional anti-AD agents.
5
. Experimental Section
5
.1 Chemistry
1
13
H and C NMR spectra were recorded using TMS as the internal standard in DMSO-d6 or CDCl
3
with a
Bruker BioSpin GmbH spectrometer at 400 MHz and 100 MHz, respectively. High resolution mass spectra
HRMS) were recorded on Shimadzu LCMS-IT-TOF spectrometer. The purities of synthesized compounds
(
were confirmed by using analytical HPLC with a dual pump Shimadzu LC-20AB system equipped with a
Ultimate-QB-C18 column (4.6 × 250 mm, 5 µm) and eluted with methanol /water (60:40 to 70:30) containing
0.1% trifluoroacetic acid at a flow rate of 0.5 mL/min.
5
.1.2 General procedures for the preparation of compounds 7a
∼ 7c
Intermediates 7a∼ 7c were prepared following the procedure previously reported [34].
5
.1.2.1 3-(2-Chloro-acetamino)-rutaecarpine (7a)
The compound 6 was reacted with chloroacetyl chloride following the general acylation procedure to give the
1
desired product 7a as a yellow solid in 83% yield. H NMR (400 MHz, DMSO): δ 11.81 (s, 1H), 10.73 (s, 1H),
8.49 (d, J = 2.3 Hz, 1H), 7.99 (dd, J = 8.8, 2.5 Hz, 1H), 7.66 (dd, J = 13.4, 8.4 Hz, 2H), 7.48 (d, J = 8.2 Hz,
12

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1H), 7.26 (t, J = 7.6 Hz, 1H), 7.09 (t, J = 7.5 Hz, 1H), 4.46 (t, J = 6.8 Hz, 2H), 4.30 (d, J = 18.0 Hz, 2H), 3.18
+
(
t, J = 6.8 Hz, 2H); HRMS (ESI): calcd for (M+H) (C20
H
15
N
4
O
2
Cl) 379.0963, found 379.0941. These data are
consistent with those reported previously [34].
5
.1.2.2 3-(2-Chloro-propionamino)-rutaecarpine (7b)
The compound 6 was reacted with 3-chloropropionyl chloride following the general acylation procedure to
1
give the desired product 7b as a yellow solid in 81% yield. H NMR (400 MHz, DMSO): δ 11.81 (s, 1H),
10.49 (s, 1H), 8.51 (d, J = 2.0 Hz, 1H), 8.01 (dd, J = 8.8, 2.3 Hz, 1H), 7.65 (t, J = 8.3 Hz, 2H), 7.48 (d, J = 8.2
Hz, 1H), 7.26 (t, J = 7.6 Hz, 1H), 7.09 (t, J = 7.5 Hz, 1H), 4.46 (t, J = 6.8 Hz, 2H), 3.92 (t, J = 6.2 Hz, 2H),
+
3
.17 (dd, J = 16.2, 9.4 Hz, 2H), 2.89 (t, J = 6.2 Hz, 2H); HRMS (ESI): calcd for (M+H) (C21
H
17
N
4
O
2
Cl)
393.1118, found 393.1097. These data are consistent with those reported previously [34].
5
.1.2.3 3-(2-Chloro-butyramino)-rutaecarpine (7c)
The compound 6 was reacted with 4-Chlorobutyryl chloride following the general acylation procedure to give
1
the desired product 7c as a yellow solid in 51% yield. H NMR (400 MHz, DMSO): δ 11.86 (s, 1H), 10.35 (s,
1H), 8.51 (s, 1H), 7.98 (d, J = 8.7 Hz, 1H), 7.66 (d, J = 8.8 Hz, 2H), 7.48 (d, J = 8.0 Hz, 1H), 7.34 – 7.24 (m,
1H), 7.10 (t, J = 6.6 Hz, 1H), 4.45 (t, J = 6.4 Hz, 2H), 3.73 (t, J = 6.4 Hz, 2H), 3.26 – 3.11 (m, 2H), 2.54 (d, J
+
=
8.2 Hz, 2H), 2.08 (dt, J = 12.4, 6.4 Hz, 2H); HRMS (ESI): calcd for (M+H) (C22
H
19
N
4
O
2
Cl) 407.1218,
found 407.1107.
5
.1.3 General procedures for the preparation of compounds 12a
∼ 12c
A suspension of EDCI (1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride, 1.32 mmol) with the
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ACCEPTED MANUSCRIPT
appropriate aromatic acid (0.66 mmol) in tetrahydrofuran (20 mL) was stirred for 30 min at room temperature,
then added the DIPEA (N,N-diisopropylethylamine, 1.32 mmol) to form a clear solution. The compound 6
(
0.33 mmol) was dissolved in THF (10 mL) and dropped into the forementioned solution. The solvent was
evaporated after stirring for 48h, filtered after adding ice water (50 mL), and then evaporated under vacuum.
The resulting crude product was purified by using flash chromatography with petroleun ether/ acetic ether as
elution solvent to afford 12a∼ 12c.
5
.1.3.1 3-(2-Phenyl-acetamino)-rutaecarpine (12a)
The compound 6 was reacted with phenylacetic acid following the general condensation procedure to give the
1
desired product 12a as a yellow solid in 78% yield. H NMR (400 MHz, DMSO): δ 11.84 (s, 1H), 10.28 (s,
1H), 8.37 (s, 1H), 7.88 (d, J = 9.5 Hz, 1H), 7.63 (d, J = 8.5 Hz, 2H), 7.42 (t, J = 6.9 Hz, 2H), 7.29 (d, J = 6.0
Hz, 4H), 7.20 (d, J = 6.1 Hz, 1H), 7.14 – 7.05 (m, 1H), 4.49 – 4.40 (m, 2H), 3.19 – 3.11 (m, 2H), 3.00 – 2.90
+
(
m, 2H); HRMS (ESI): calcd for (M+H) (C26
H
20
N
4
2
O ) 421.1608, found 421.1567.
5
.1.3.2 3-(2-Phenyl-propionamino)-rutaecarpine (12b)
The compound 6 was reacted with 3-phenylpropionic acid following the general condensation procedure to
1
give the desired product 12b as a yellow solid in 69% yield. H NMR (400 MHz, DMSO): δ 11.84 (s, 1H),
10.28 (s, 1H), 8.47 (s, 1H), 7.98 (d, J = 9.5 Hz, 1H), 7.65 (d, J = 8.5 Hz, 2H), 7.47 (t, J = 6.9 Hz, 2H), 7.29 (d,
J = 6.0 Hz, 4H), 7.20 (d, J = 6.1 Hz, 1H), 7.14 – 7.05 (m, 1H), 4.49 – 4.40 (m, 2H), 3.21 – 3.11 (m, 2H), 3.00
+
–
2.90 (m, 2H), 2.72 – 2.64 (m, 2H); HRMS (ESI): calcd for (M+H) (C27
H
22
N
4
2
O ) 435.1823, found 435.1767.
5
.1.3.3 3-(2-Phenyl-butyramino)-rutaecarpine (12c)
14

ACCEPTED MANUSCRIPT
The compound 6 was reacted with 4-phenylbutyric acid following the general condensation procedure to give
1
the desired product 12c as a yellow solid in 81% yield. H NMR (400 MHz, DMSO): δ 11.70 (s, 1H), 10.24 (s,
1H), 8.50 (s, 1H), 7.99 (d, J = 10.0 Hz, 1H), 7.63 (dd, J = 14.3, 8.2 Hz, 2H), 7.53 – 7.42 (m, 2H), 7.33 – 7.23
(
m, 3H), 7.19 (d, J = 7.6 Hz, 1H), 7.13 – 7.03 (m, 2H), 5.67 (s, 2H), 4.51 – 4.37 (m, 2H), 3.22 – 3.10 (m, 2H),
+
2
.11 (d, J = 9.0 Hz, 2H), 1.97 – 1.89 (m, 2H); HRMS (ESI): calcd for (M+H) (C28
H
24
N
4
O
2
) 449.1953, found
449.1687.
5
.1.4 General procedures for the preparation of compounds 8a∼ 8c, 9l, 10l and 11l
A solution of DDQ (2,3-dichloro-5,6-dicyano-1,4-benzoquinone, 5.2 mmol) in dioxane (10 mL) was dropped
to a hot solution of intermediates 7a∼ 7c or 12a∼ 12c (2.5 mmol) in DMSO (1.0 mL) and dioxane (250 mL) for
30 min. The solvent was evaporated after a reflux for 12h, and the residue was washed by a solution of KOH
(
1.5g) in water (25 mL) until all DDQ-2H was cleared. The resulting crude product was purified by
recrystallization from EtOH/DMF (5:1 v/v). The product was characterized, and the data of 8a∼ 8b are
consistent with those reported previously [34].
5
.1.4.1 3-(2-Chloro-acetamino)-7,8-dehydrorutaecarpine (8a)
The compound 7a was reacted with DDQ following the general dehydrogenation procedure to give the desired
1
product 8a as a green solid in 86% yield. H NMR (400 MHz, DMSO): δ 12.68 (s, 1H), 10.69 (s,1H), 8.72 (d,
J = 0.8 Hz, 1H), 8.63 (d, J = 7.5 Hz, 1H), 8.18 (d, J = 7.9 Hz, 1H), 8.08 (d, J = 7.8 Hz, 1H), 7.85 (dd, J = 10.6,
8.7 Hz, 2H), 7.69 (d, J = 8.1 Hz, 1H), 7.50 (t, J = 7.3 Hz, 1H), 7.30 (t, J = 7.3 Hz, 1H), 4.34 (s, 2H); HRMS
+
(
ESI): calcd for (M+H) (C H N O Cl) 377.0805, found 377.0763. These data are consistent with those
20
13
4
2
reported previously [34].
15

ACCEPTED MANUSCRIPT
5
.1.4.2 3-(2-Chloro-propionamino)-7,8-dehydrorutaecarpine (8b)
The compound 7b was reacted with DDQ following the general dehydrogenation procedure to give the
1
desired product 8b as a green solid in 85% yield. H NMR (400 MHz, DMSO): δ 12.78 (s, 1H), 10.53 (s, 1H),
8.77 (d, J = 1.8 Hz, 1H), 8.66 (d, J = 7.5 Hz, 1H), 8.21 (d, J = 7.9 Hz, 1H), 8.11 (dd, J = 8.9, 2.1 Hz, 1H), 7.89
(
t, J = 7.2 Hz, 2H), 7.71 (d, J = 8.2 Hz, 1H), 7.53 (t, J = 7.5 Hz, 1H), 7.32 (t, J = 7.6 Hz, 1H), 3.94 (t, J = 6.2
+
Hz, 2H), 2.92 (t, J = 6.1 Hz, 2H); HRMS (ESI): calcd for (M+H) (C21
H
15
N
4
O
2
Cl) 391.0905, found 391.0863.
5
.1.4.3 3-(2-Chloro-butyramino)-7,8-dehydrorutaecarpine (8c)
The compound 7c was reacted with DDQ following the general dehydrogenation procedure to give the desired
1
product 8c as a green solid in 76% yield. H NMR (400 MHz, DMSO): δ 12.86 (s, 1H), 10.46 (s, 0H), 8.76 (s,
0H), 8.68 (d, J = 7.0 Hz, 1H), 8.22 (d, J = 7.4 Hz, 1H), 8.10 (d, J = 8.9 Hz, 1H), 7.94 (d, J = 7.2 Hz, 1H), 7.88
(
d, J = 8.8 Hz, 0H), 7.72 (d, J = 7.1 Hz, 1H), 7.58 – 7.51 (m, 1H), 7.33 (t, J = 7.6 Hz, 1H), 3.75 (t, J = 5.9 Hz,
+
1
H), 2.64 – 2.54 (m, 1H), 2.17 – 2.03 (m, 1H); HRMS (ESI): calcd for (M+H) (C22
H
17
N
4
O
2
Cl) 405.1105,
found 405.1033.
5
.1.4.4 3-(2-Phenyl-acetamino)-7,8-dehydrorutaecarpine (9l)
The compound 12a was reacted with DDQ following the general dehydrogenation procedure to give the
1
desired product 9l as a brown solid in 86% yield. H NMR (400 MHz, DMSO): δ 12.69 (s, 1H), 11.45 (s, 1H),
9
.13 (d, J = 5.1 Hz, 2H), 8.76 (d, J = 7.5 Hz, 1H), 8.75 – 8.69 (m, 1H), 8.62 (d, J = 7.5 Hz, 2H), 8.26 (t, J =
.8 Hz, 2H), 8.18 (d, J = 8.1 Hz, 2H), 8.10 (d, J = 9.6 Hz, 1H), 7.90 (s, 1H), 7.84 (d, J = 7.6 Hz, 1H), 7.70 (d,
6
13
J = 8.2 Hz, 1H), 7.54 – 7.46 (m, 2H), 7.30 (t, J = 7.2 Hz, 2H), 5.79 (s, 2H); C NMR (101 MHz, DMSO): δ
16

ACCEPTED MANUSCRIPT
168.04, 158.28, 148.56, 143.68, 139.77, 139.03, 135.56, 129.42, 128.88, 127.14, 126.83, 126.35, 121.80,
120.65, 120.34, 119.24, 117.52, 116.02, 115.71, 114.90, 112.64, 112.08, 107.92, 40.71. Purity: 98.6% by
+
HPLC. HRMS (ESI): calcd for (M+H) (C26
H
18
N
4
O
2
) 419.1545, found 419.1533.
5
.1.4.5 3-(2-Phenyl-propionamino)-7,8-dehydrorutaecarpine (10l)
The compound 12b was reacted with DDQ following the general dehydrogenation procedure to give the
1
desired product 10l as a brown solid in 80% yield. H NMR (400 MHz, DMSO): δ 11.83 (s, 1H), 10.55 (s,
1H), 8.48 (d, J = 2.1 Hz, 1H), 8.01 (dd, J = 8.8, 2.2 Hz, 1H), 7.65 (dd, J = 8.3, 5.2 Hz, 2H), 7.48 (s, 2H), 7.37
1
3
(
t, J = 8.0 Hz, 3H), 7.31 – 7.23 (m, 3H), 7.17 – 7.02 (m, 2H), 4.45 (t, J = 6.7 Hz, 2H), 3.22 – 3.07 (m, 2H); C
NMR (101 MHz, DMSO): δ 169.50, 164.76, 158.28, 148.10, 139.82, 135.56, 135.10, 129.28, 128.89, 127.48,
1
4
4
26.62, 126.51, 121.79, 120.80, 120.46, 117.62, 116.58, 116.00, 115.35, 115.15, 112.68, 112.45, 108.07,
+
7.39, 43.53. Purity: 97.8% by HPLC. HRMS (ESI): calcd for (M+H) (C27
20 4 2
H N O ) 433.1615, found
33.1603.
5
.1.4.6 3-(2-Phenyl-butyramino)-7,8-dehydrorutaecarpine (11l)
The compound 12c was reacted with DDQ following the general dehydrogenation procedure to give the
1
desired product 11l as a brown solid in 72% yield. H NMR (400 MHz, DMSO): δ 11.83 (s, 1H), 10.24 (s,
1H), 8.50 (d, J = 2.3 Hz, 1H), 7.98 (dd, J = 8.7, 2.3 Hz, 1H), 7.73 – 7.60 (m, 2H), 7.55 – 7.42 (m, 2H), 7.30
(
dd, J = 14.1, 6.7 Hz, 4H), 7.20 (dd, J = 10.1, 7.3 Hz, 2H), 7.15 – 7.00 (m, 2H), 4.51 – 4.41 (m, 2H), 3.24 –
1
3
3
1
1
.12 (m, 2H), 2.45 – 2.34 (m, 2H); C NMR (101 MHz, DMSO): δ 169.29, 160.31, 150.75, 143.96, 142.89,
38.54, 137.16, 135.75, 129.10, 128.28, 126.97, 126.84, 126.54, 126.02, 124.85, 124.55, 120.80, 119.76,
19.63, 117.39, 115.13, 112.43, 101.57, 43.28, 40.83, 18.87. Purity: 97.7% by HPLC. HRMS (ESI): calcd for
17

ACCEPTED MANUSCRIPT
+
(
M+H) (C H N O ) 447.1935, found 447.1813.
28 22 4 2
5
.1.5 General procedures for the preparation of compounds 9a∼ 9c, 9j, 10a∼ 10c, 10j, 11a and 11c
A suspension of compounds 8a∼ 8c (1.0 mmol) in appropriate N-heterocyclic amine (12 mL) was heated under
reflux for 8h, cooled to 0 ºC, filtered after adding ether (30 mL), washed with ether, and then evaporated under
vacuum. The resulting crude product was purified by recrystallization from EtOH/DMF (5:1 v/v) to afford
9a∼ 9c, 9j, 10a∼ 10c, 10j, 11a and 11c.
5
.1.5.1 3-(2-N-Pyridyl-acetamino)-7,8-dehydrorutaecarpine (9a)
The compound 8a was reacted with pyridine following the general procedure to give the desired product 9a as
1
a brown solid in 64% yield. H NMR (400 MHz, DMSO): δ 12.69 (s, 1H), 11.45 (s, 1H), 9.13 (d, J = 5.1 Hz,
2
8
=
H), 8.76 (d, J = 7.5 Hz, 1H), 8.72 (d, J = 8.3 Hz, 1H), 8.60 (d, J = 15.9, 4.6 Hz, 1H), 8.26 (t, J = 6.8 Hz, 2H),
.18 (d, J = 8.1 Hz, 1H), 8.10 (d, J = 9.6 Hz, 1H), 7.89 (d, J = 8.8 Hz, 1H), 7.84 (d, J = 7.6 Hz, 1H), 7.70 (d, J
1
3
8.2 Hz, 1H), 7.54 – 7.46 (m, 1H), 7.30 (t, J = 7.2 Hz, 1H), 5.79 (s, 2H); C NMR (101 MHz, DMSO): δ
163.45, 158.34, 146.47, 146.27, 144.14, 139.87, 139.35, 134.90, 129.45, 127.54, 127.25, 127.18, 126.57,
121.84, 120.83, 120.51, 119.52, 117.63, 116.11, 115.34, 112.71, 108.18, 62.76. Purity: 96.7% by HPLC.
+
HRMS (ESI): calcd for (M) (C25
H
18
N
5
2
O ) 420.1455, found 420.1470.
5
.1.5.2 3-(2-(3-Fluoropyrid-1-yl)-acetamino)-7,8-dehydrorutaecarpine (9b)
The compound 8a was reacted with 3-fluoropyridine following the general procedure to give the desired
1
product 9b as a brown solid in 89% yield. H NMR (400 MHz, DMSO): δ 12.70 (s, 1H), 11.66 (s, 1H), 9.59 (s,
1H), 9.12 (d, J = 5.6 Hz, 1H), 8.80 (d, J = 13.2 Hz, 2H), 8.61 (d, J = 8.1 Hz, 1H), 8.39 (d, J = 7.4 Hz, 1H),
18

ACCEPTED MANUSCRIPT
8.18 (d, J = 7.3 Hz, 1H), 8.12 (d, J = 10.1 Hz, 1H), 7.89 (d, J = 9.7 Hz, 1H), 7.84 (d, J = 8.3 Hz, 1H), 7.70 (d,
1
3
J = 9.1 Hz, 1H), 7.53 – 7.47 (m, 1H), 7.35 – 7.23 (m, 1H), 5.85 (s, 2H); C NMR (101 MHz, DMSO): δ
165.32, 163.31, 160.65, 158.84, 144.45, 140.47, 139.92, 137.21, 136.95, 135.25, 134.51, 129.94, 129.41,
127.86, 127.66, 127.09, 122.39, 121.28, 121.03, 118.15, 116.61, 116.14, 113.26, 108.67, 63.09. Purity: 97.8%
+
by HPLC. HRMS (ESI): calcd for (M) (C25
H
17
N
5
O
2
F) 438.1361, found 438.1347.
5
.1.5.3 3-(2-(1-Methylimidazol-3-yl)-acetamino)-7,8-dehydrorutaecarpine (9c)
The compound 8a was reacted with 1-methylimidazole following the general procedure to give the desired
1
product 9c as a brown solid in 78% yield. H NMR (400 MHz, DMSO): δ 12.69 (s, 1H), 11.33 (s, 1H), 9.21 (s,
1
H), 8.78 (s, 1H), 8.62 (d, J = 7.2 Hz, 1H), 8.18 (d, J = 7.5 Hz, 1H), 8.10 (d, J = 8.6 Hz, 1H), 7.86 (dd, J =
6.2, 8.4 Hz, 3H), 7.77 (s, 1H), 7.70 (d, J = 8.2 Hz, 1H), 7.50 (t, J = 7.0 Hz, 1H), 7.30 (t, J = 6.9 Hz, 1H), 5.35
1
13
(
s, 2H), 3.95 (s, 3H); C NMR (101 MHz, DMSO): δ 163.92, 158.22, 143.90, 139.78, 139.08, 137.93, 135.07,
1
1
29.34, 127.14, 126.88, 126.37, 123.88, 123.05, 121.76, 120.65, 120.33, 119.32, 117.46, 115.94, 115.14,
+
12.65, 107.91, 51.35, 35.86. Purity: 99.0% by HPLC. HRMS (ESI): calcd for (M) (C24
H
19
N
6
O
2
) 423.1564,
found 423.1568.
5
.1.5.4 3-(2-(Pyridin-3-yloxy)-acetamino)-7,8-dehydrorutaecarpine (9j)
The compound 8a was reacted with 3-hydroxypyridine in DMSO (3 mL) following the general procedure to
1
give the desired product 9j as a brown solid in 98% yield. H NMR (400 MHz, DMSO): δ 12.70 (s, 1H), 11.50
(
s, 1H), 8.76 (s, 1H), 8.61 (s, 2H), 8.55 (d, J = 27.5 Hz, 1H), 8.13 (dd, J = 17.0, 7.3 Hz, 2H), 8.07 – 8.02 (m,
1H), 7.98 (d, J = 4.0 Hz, 1H), 7.83 (dd, J = 25.1, 6.9 Hz, 2H), 7.69 (d, J = 7.7 Hz, 1H), 7.50 (d, J = 0.8 Hz,
1
3
1
H), 7.30 (d, J = 6.9 Hz, 1H), 5.69 (s, 2H); C NMR (101 MHz, DMSO): δ 163.38, 158.20, 144.19, 143.99,
19

ACCEPTED MANUSCRIPT
139.79, 139.18, 134.81, 134.63, 132.01, 129.34, 127.76, 127.11, 127.02, 126.41, 121.77, 120.65, 120.38,
119.37, 117.52, 115.98, 115.22, 112.69, 108.02, 107.80, 62.03. Purity: 97.8% by HPLC. HRMS (ESI): calcd
-
for (M-H) (C25
H
17
N
5
O
3
) 434.1259, found 434.1265.
5
.1.5.5 3-(2-N-Pyridyl-propionamino)-7,8-dehydrorutaecarpine (10a)
The compound 8b was reacted with pyridine following the general procedure to give the desired product 10a
1
as a brown solid in 64% yield. H NMR (400 MHz, DMSO): δ 12.70 (s, 1H), 10.93 (s, 1H), 9.23 (d, J = 4.5
Hz, 2H), 8.74 (s, 1H), 8.60 (d, J = 7.4 Hz, 2H), 8.19 (d, J = 6.1 Hz, 3H), 8.04 (d, J = 8.4 Hz, 1H), 7.83 (s, 2H),
1
3
7
.68 (d, J = 7.8 Hz, 1H), 7.49 (t, J = 6.5 Hz, 1H), 7.29 (t, J = 6.7 Hz, 1H), 4.98 (s, 2H), 3.29 (s, 2H); C NMR
(
101 MHz, DMSO): δ 168.49, 158.82, 146.22, 145.89, 140.36, 139.59, 135.97, 129.80, 128.28, 127.88,
127.19, 127.10, 122.31, 121.34, 121.02, 120.04, 118.14, 116.48, 115.51, 113.21, 108.67, 57.37, 37.10. Purity:
+
9
9.2% by HPLC. HRMS (ESI): calcd for (M) (C26
H
20
N
5
2
O ) 434.1612, found 434.1608.
5
.1.5.6 3-(2-(3-Fluoropyrid-1-yl))-propionamino)-7,8-dehydrorutaecarpine (10b)
The compound 8b was reacted with 3-fluoropyridine following the general procedure to give the desired
1
product 10b as a brown solid in 60% yield. H NMR (400 MHz, DMSO): δ 12.70 (s, 1H), 10.93 (s, 1H), 9.23
(
d, J = 4.5 Hz, 2H), 8.74 (s, 1H), 8.61 (s, 1H), 8.19 (d, J = 6.1 Hz, 3H), 8.04 (d, J = 8.4 Hz, 1H), 7.83 (s, 2H),
1
3
7
.68 (d, J = 7.8 Hz, 1H), 7.49 (t, J = 7.0 Hz, 1H), 7.29 (t, J = 6.7 Hz, 1H), 4.98 (m, 2H), 3.29 (m, 2H); C
NMR (101 MHz, DMSO): δ 165.32, 163.31, 160.65, 158.84, 144.45, 140.47, 139.92, 137.21, 136.95, 135.25,
1
1
4
34.51, 129.94, 129.41, 127.86, 127.66, 127.09, 122.39, 121.28, 121.03, 118.15, 116.61, 116.14, 113.26,
+
08.67, 63.09, 44.00. Purity: 98.8% by HPLC. HRMS (ESI): calcd for (M) (C H N O F) 452.1517, found
26
19
5
2
52.1530.
20

ACCEPTED MANUSCRIPT
5
.1.5.7 3-(2-(1-Methylimidazol-3-yl)-propionamino)-7,8-dehydrorutaecarpine (10c)
The compound 8b was reacted with 1-methylimidazole following the general procedure to give the desired
1
product 10c as a brown solid in 56% yield. H NMR (400 MHz, DMSO): δ 12.69 (s, 1H), 10.93 (s, 1H), 9.27
(
(
(
s, 1H), 8.80 (s, 1H), 8.61 (d, J = 7.5 Hz, 1H), 8.17 (d, J = 7.9 Hz, 1H), 8.08 (d, J = 8.0 Hz, 1H), 7.87 – 7.80
m, 3H), 7.74 – 7.66 (m, 2H), 7.49 (t, J = 7.6 Hz, 1H), 7.30 (t, J = 7.4 Hz, 1H), 4.54 (s, 2H), 3.88 (s, 3H), 3.12
1
3
s, 2H); C NMR (101 MHz, DMSO): δ 168.19, 158.32, 143.73, 139.81, 139.06, 137.06, 135.63, 129.45,
1
1
27.36, 126.75, 126.42, 123.46, 122.48, 121.82, 120.72, 120.41, 119.27, 117.55, 115.98, 114.93, 112.68,
+
08.00, 44.97, 35.97, 35.72. Purity: 99.3% by HPLC. HRMS (ESI): calcd for (M) (C25
H
21
N
6
O
2
) 437.1721,
found 437.1729.
5
.1.5.8 3-(2-(Pyridin-3-yloxy)-acetamino)-7,8-dehydrorutaecarpine (10j)
The compound 8b was reacted with 3-hydroxypyridine in DMSO (3 mL) following the general procedure to
1
give the desired product 10j as a brown solid in 91% yield. H NMR (400 MHz, DMSO): δ 12.71 (s, 1H),
1
2
7
1
1
0.77 (s, 1H), 8.75 (s, 1H), 8.67 (s, 1H), 8.61 (d, J = 7.8 Hz, 1H), 8.17 (d, J = 7.8 Hz, 1H), 8.02 (d, J = 7.9 Hz,
H), 7.97 (d, J = 6.4 Hz, 1H), 7.83 (d, J = 7.2 Hz, 2H), 7.68 (d, J = 7.9 Hz, 1H), 7.52 – 7.47 (m, 1H), 7.35 –
13
.25 (m, 1H), 4.90 (d, J = 0.6 Hz, 2H), 3.24 (d, J = 1.0 Hz, 2H); C NMR (101 MHz, DMSO): δ 167.76,
58.17, 156.90, 143.56, 139.71, 138.90, 135.95, 135.35, 133.30, 131.47, 129.26, 128.18, 127.14, 126.64,
26.35, 121.69, 120.61, 120.32, 119.27, 117.46, 115.84, 114.82, 112.60, 107.90, 56.82, 36.81. Purity: 99.6%
+
by HPLC. HRMS (ESI): calcd for (M+H) (C26
H
19
N
5
O
3
) 450.1561, found 450.1548.
5
.1.5.9 3-(2-N-Pyridyl-butyramino)-7,8-dehydrorutaecarpine (11a)
21

ACCEPTED MANUSCRIPT
The compound 8c was reacted with pyridine following the general procedure to give the desired product 11a
1
as a brown solid in 79% yield. H NMR (400 MHz, DMSO): δ 12.70 (s, 1H), 10.48 (s, 1H), 9.16 (d, J = 5.7
Hz, 2H), 8.73 (s, 1H), 8.62 (d, J = 6.6 Hz, 2H), 8.26 – 8.13 (m, 3H), 8.04 (d, J = 8.8 Hz, 1H), 7.84 (d, J = 8.1
Hz, 2H), 7.69 (d, J = 8.3 Hz, 1H), 7.57 – 7.46 (m, 1H), 7.36 – 7.25 (m, 1H), 4.73 (t, J = 7.6 Hz, 2H), 2.49 –
1
3
2
1
1
.41 (m, 2H), 2.37 – 2.29 (m, 2H); C NMR (101 MHz, DMSO): δ 169.29, 160.31, 150.75, 143.96, 142.89,
38.54, 137.16, 135.75, 129.10, 128.28, 126.97, 126.54, 126.02, 124.85, 124.55, 120.80, 119.76, 119.63,
+
17.39, 115.13, 112.43, 101.57, 43.28, 40.83, 18.87. Purity: 98.9% by HPLC. HRMS (ESI): calcd for (M)
(
27 22 5 2
C H N O ) 448.1768, found 448.1774.
5
.1.5.10 3-(2-(1-Methylimidazol-3-yl)-butyramino)-7,8-dehydrorutaecarpine (11c)
The compound 8c was reacted with 1-methylimidazole following the general procedure to give the desired
1
product 11c as a brown solid in 50% yield. H NMR (400 MHz, DMSO): δ 12.69 (s, 1H), 10.45 (s, 1H), 9.20
(
s, 1H), 8.76 (s, 1H), 8.61 (d, J = 6.2 Hz, 1H), 8.17 (d, J = 6.4 Hz, 1H), 8.09 – 8.00 (m, 1H), 7.83 (s, 2H), 7.77
7.64 (m, 3H), 7.57 – 7.41 (m, 1H), 7.37 – 7.23 (m, 1H), 4.28 (t, J = 11.4 Hz, 2H), 3.85 (s, 3H), 2.23 – 2.10
–
1
3
(
m, 2H), 1.91 (t, J = 5.3 Hz, 2H); C NMR (101 MHz, DMSO): δ 171.90, 158.28, 143.55, 139.76, 138.95,
129.38, 127.78, 127.27, 126.56, 126.38, 123.59, 122.32, 121.77, 120.81, 120.62, 120.39, 117.52, 116.68,
112.62, 112.49, 107.94, 99.49, 48.54, 35.73, 31.23, 20.98. Purity: 98.7% by HPLC. HRMS (ESI): calcd for
+
(
M) (C26
H
23
N
6
O
2
) 451.1877, found 451.1854.
5
.1.6 General procedures for the preparation of compounds 9d∼ 9i, 9k, 10d∼ 10i, 10k and 11f
The appropriate secondary amine (1.0 mL) was added to a suspension of compounds 8a∼ 8c (1.0 mmol) and
NaI (0.15 g) in EtOH (30 mL). After a reflux for 8h, the mixture was cooled to 0 ºC, filtered, washed with
22

ACCEPTED MANUSCRIPT
EtOH and water, and then evaporated under vacuum. The resulting crude product was purified by using flash
chromatography with chloroform/methanol as elution solvent. Compounds 9e∼ 9g were synthesized, and their
characterization data are consistent with those reported previously [34].
5
.1.6.1 3-(2-Dimethylamino-acetamino)-7,8-dehydrorutaecarpine (9d)
The compound 8a was reacted with excess dimethylamine following the general procedure to give the desired
1
product 9d as a yellow solid in 71% yield. H NMR (400 MHz, DMSO): δ 12.67 (s, 1H), 10.15 (s, 1H), 8.80
(
d, J = 2.0 Hz, 1H), 8.62 (d, J = 7.5 Hz, 1H), 8.17 (d, J = 8.1 Hz, 2H), 7.85 – 7.79 (m, 2H), 7.69 (d, J = 8.1 Hz,
13
1
H), 7.49 (t, J = 7.6 Hz, 1H), 7.30 (t, J = 7.5 Hz, 1H), 3.16 (s, 2H), 2.33 (s, 6H); C NMR (101 MHz, DMSO):
δ 168.88, 158.36, 143.77, 139.82, 139.11 , 135.46, 129.47, 127.80, 126.55 , 121.86, 120.73, 120.42, 119.29,
117.60, 116.02 , 115.43, 112.68 , 107.98 , 63.26, 45.33. Purity: 99.8% by HPLC. HRMS (ESI): calcd for
+
(
M+H) (C22
H
19
N
5
O
2
) 386.1612, found 386.1621.
5
.1.6.2 3-(2-N-Morpholinyl-acetamino)-7,8-dehydrorutaecarpine (9h)
The compound 8a was reacted with excess morpholine following the general procedure to give the desired
1
product 9h as a yellow solid in 80% yield. H NMR (400 MHz, DMSO): δ 12.67 (s, 1H), 10.15 (s, 1H), 8.73
(
d, J = 12.1 Hz, 1H), 8.62 (d, J = 7.2 Hz, 1H), 8.20 – 8.13 (m, 2H), 7.87 – 7.80 (m, 2H), 7.69 (d, J = 8.1 Hz,
13
1
H), 7.49 (t, J = 7.5 Hz, 1H), 7.30 (t, J = 7.1 Hz, 1H), 3.67 (s, 4H), 3.21 (s, 2H), 2.56 (s, 4H); C NMR (101
MHz, DMSO): δ 168.30, 158.36, 143.83, 139.83, 139.14, 135.30, 129.47, 127.80, 126.71, 126.44, 121.86,
120.74, 120.43, 119.32, 117.61, 116.02, 115.49, 112.69, 108.00, 66.05, 62.05, 53.17. Purity: 99.5% by HPLC.
+
HRMS (ESI): calcd for (M+H) (C H N O ) 428.1717, found 428.1736.
24
21
5
3
23

ACCEPTED MANUSCRIPT
5
.1.6.3 3-(2-(4-Methylpiperazin-1-yl)-acetamino)-7,8-dehydrorutaecarpine (9i)
The compound 8a was reacted with excess N-methyl piperazine following the general procedure to give the
1
desired product 9i as a yellow solid in 74% yield. H NMR (400 MHz, CDCl
3
): δ 9.86 (s, 1H), 9.46 (s, 1H),
8.74 (d, J = 7.6 Hz, 1H), 8.50 (d, J = 8.8 Hz, 1H), 8.28 (s, 1H), 8.04 (t, J = 7.7 Hz, 1H), 7.82 (d, J = 9.1 Hz,
1
3
1
H), 7.60 – 7.46 (m, 3H), 7.37 – 7.29 (m, 1H), 3.21 (s, 2H), 2.71 (s, 4H), 2.57 (s, 4H), 2.37 (s, 3H); C NMR
(
101 MHz, DMSO): δ 168.43, 158.28, 143.76, 139.79, 139.04, 135.25, 129.43, 127.62, 126.66, 126.35,
121.82, 120.66, 120.35, 119.26, 117.53, 115.97, 115.31, 112.66, 107.90, 61.78, 54.50, 52.67, 45.70. Purity:
+
9
6.6% by HPLC. HRMS (ESI): calcd for (M+H) (C25
H
24
N
6
O
2
) 441.2034, found 441.2022.
5
.1.6.4 3-(2-Phenylamino-acetamino)-7,8-dehydrorutaecarpine (9k)
The compound 8a was reacted with excess aniline following the general procedure to give the desired product
1
9
8
1
k as a yellow solid in 68% yield. H NMR (400 MHz, DMSO): δ 12.70 (s, 1H), 10.42 (s, 1H), 8.74 (s, 1H),
.70 – 8.57 (m, 1H), 8.19 (s, 1H), 8.11 (dd, J = 20.9, 6.3 Hz, 2H), 7.87 – 7.80 (m, 2H), 7.69 (d, J = 8.9 Hz,
H), 7.50 (t, J = 7.1 Hz, 1H), 7.30 (t, J = 8.2 Hz, 1H), 7.12 (t, J = 7.2 Hz, 2H), 6.65 (d, J = 8.0 Hz, 1H), 6.59
1
3
(
d, J = 7.0 Hz, 1H), 4.35 (d, J = 0.6 Hz, 1H), 4.03 – 3.88 (m, 2H); C NMR (101 MHz, DMSO): δ 168.04,
158.28, 148.56, 143.68, 139.77, 139.03, 135.56, 129.42, 128.88, 127.14, 126.83, 126.35, 121.80, 120.65,
120.34, 119.24, 117.52, 116.02, 115.71, 114.90, 112.64, 112.08, 107.92, 40.71. Purity: 99.6% by HPLC.
-
HRMS (ESI): calcd for (M-H) (C26
H
19
N
5
O
2
) 432.1466, found 432.1486.
5
.1.6.5 3-(2-Dimethylamino-propionamino)-7,8-dehydrorutaecarpine (10d)
The compound 8b was reacted with excess dimethylamine following the general procedure to give the desired
1
product 10d as a yellow solid in 63% yield. H NMR (400 MHz, DMSO): δ 12.64 (s, 1H), 10.38 (s, 1H), 8.71
24

ACCEPTED MANUSCRIPT
(
s, 1H), 8.61 (d, J = 7.5 Hz, 1H), 8.16 (d, J = 7.9 Hz, 1H), 8.07 (d, J = 8.8 Hz, 1H), 7.82 (t, J = 8.4 Hz, 2H),
7
7
1
5
4
.69 (d, J = 8.2 Hz, 1H), 7.49 (t, J = 7.6 Hz, 1H), 7.29 (t, J = 7.4 Hz, 1H), 2.62 (t, J = 6.7 Hz, 2H), 2.53 (d, J =
13
.2 Hz, 2H), 2.21 (s, 6H); C NMR (101 MHz, DMSO): δ 170.29, 158.29, 143.53, 139.79, 138.96, 135.94,
29.46, 127.20, 126.73, 126.30, 121.85, 120.62, 120.33, 119.18, 117.51, 116.05, 114.75, 112.65, 107.86,
+
5.03, 44.89, 34.79. Purity: 99.3% by HPLC. HRMS (ESI): calcd for (M+H) (C23
21 5 2
H N O ) 400.1768, found
00.1765.
5
.1.6.6 3-(2-Diethylamino-propionamino)-7,8-dehydrorutaecarpine (10e)
The compound 8b was reacted with excess diethylamine following the general procedure to give the desired
1
product 10e as a yellow solid in 69% yield. H NMR (400 MHz, CDCl
3
): δ 11.50 (s, 1H), 10.04 (s, 1H), 8.68
(
t, J = 6.1 Hz, 1H), 8.33 (s, 1H), 8.32 – 8.24 (m, 1H), 8.01 – 7.96 (m, 1H), 7.79 – 7.71 (m, 1H), 7.53 (d, J =
7.4 Hz, 1H), 7.50 – 7.45 (m, 2H), 7.36 – 7.27 (m, 1H), 2.88 (m, J = 4.6 Hz, 2H), 2.81 – 2.72 (t, 4H), 2.62 (m,
13
J = 4.9 Hz, 2H), 1.27 – 1.15 (m, 6H); C NMR (101 MHz, DMSO): δ 170.55, 158.33, 143.55, 139.80, 139.00,
1
1
4
35.98, 129.48, 127.23, 126.83, 126.37, 121.86, 120.70, 120.39, 119.22, 117.56, 116.10, 114.70, 112.66,
+
07.95, 48.30, 46.11, 34.17, 11.72. Purity: 98.0% by HPLC. HRMS (ESI): calcd for (M+H) (C25
28.2081, found 428.2097.
25 5 2
H N O )
5
.1.6.7 3-(2-N-Pyrrolyl-propionamino)-7,8-dehydrorutaecarpine (10f)
The compound 8b was reacted with excess pyrrolidine following the general procedure to give the desired
1
product 10f as a yellow solid in 73% yield. H NMR (400 MHz, DMSO): δ 12.65 (s, 1H), 10.43 (s, 1H), 8.72
(
d, J = 2.2 Hz, 1H), 8.62 (d, J = 7.5 Hz, 1H), 8.17 (d, J = 7.9 Hz, 1H), 8.07 (dd, J = 8.9, 2.3 Hz, 1H), 7.83 (dd,
J = 8.2, 6.0 Hz, 2H), 7.69 (d, J = 8.2 Hz, 1H), 7.49 (t, J = 7.6 Hz, 1H), 7.30 (t, J = 7.5 Hz, 1H), 2.78 (t, J = 7.0
25

ACCEPTED MANUSCRIPT
13
Hz, 2H), 2.57 (t, J = 6.9 Hz, 2H), 2.54 (t, 4H), 1.70 (m, J = 3.0 Hz, 4H); C NMR (101 MHz, DMSO): δ
170.29, 158.32, 143.54, 139.79, 139.00, 135.97, 129.48, 127.23, 126.80, 126.36, 121.85, 120.69, 120.38,
119.21, 117.56, 116.08, 114.71, 112.66, 107.94, 53.38, 51.49, 36.14, 23.14. Purity: 98.7% by HPLC. HRMS
+
(
ESI): calcd for (M+H) (C25
H
23
N
5
O
2
) 426.1925, found 426.1918.
5
.1.6.8 3-(2-N-Piperidyl-propionamino)-7,8-dehydrorutaecarpine (10g)
The compound 8b was reacted with excess piperidine following the general procedure to give the desired
1
product 10g as a yellow solid in 77% yield. H NMR (400 MHz, DMSO): δ 12.65 (s, 1H), 10.51 (s, 1H), 8.71
(
d, J = 1.8 Hz, 1H), 8.62 (d, J = 7.5 Hz, 1H), 8.17 (d, J = 7.9 Hz, 1H), 8.06 (dd, J = 9.0, 2.2 Hz, 1H), 7.83 (t, J
8.2 Hz, 2H), 7.69 (d, J = 8.1 Hz, 1H), 7.49 (t, J = 7.6 Hz, 1H), 7.30 (t, J = 7.5 Hz, 1H), 2.69 – 2.63 (m, 2H),
=
13
2
.54 (d, J = 6.7 Hz, 2H), 2.42 (s, 4H), 1.58 – 1.48 (m, 4H), 1.45 – 1.35 (m, 2H); C NMR (101 MHz, DMSO):
δ 170.45, 158.32, 143.54, 139.80, 139.00, 135.95, 129.48, 127.19, 126.84, 126.37, 121.86, 120.70, 120.38,
119.21, 117.55, 116.09, 114.66, 112.66, 107.95, 54.39, 53.63, 34.12, 25.61, 23.98. Purity: 99.7% by HPLC.
+
HRMS (ESI): calcd for (M+H) (C26
H
25
N
5
O
2
) 440.2081, found 440.2103.
5
.1.6.9 3-(2-N-Morpholinyl-propionamino)-7,8-dehydrorutaecarpine (10h)
The compound 8b was reacted with excess morpholine following the general procedure to give the desired
1
product 10h as a yellow solid in 68% yield. H NMR (400 MHz, DMSO): δ 12.67 (s, 1H), 10.41 (s, 1H), 8.71
(
d, J = 2.4 Hz, 1H), 8.61 (d, J = 7.5 Hz, 1H), 8.16 (d, J = 8.0 Hz, 1H), 8.06 (dd, J = 9.0, 2.5 Hz, 1H), 7.82 (dd,
J = 8.2, 6.3 Hz, 2H), 7.68 (d, J = 8.3 Hz, 1H), 7.49 (t, J = 7.7 Hz, 1H), 7.29 (t, J = 7.5 Hz, 1H), 3.64 – 3.54 (t,
1
3
4
H), 2.75 – 2.65 (t, 2H), 2.56 (t, J = 6.8 Hz, 2H), 2.48 – 2.38 (t, 4H); C NMR (101 MHz, DMSO): δ 170.20,
158.31, 143.56, 139.79, 139.00, 135.90, 129.47, 127.22, 126.80, 126.35, 121.84, 120.68, 120.37, 119.21,
26

ACCEPTED MANUSCRIPT
117.55, 116.07, 114.73, 112.66, 107.92, 66.18, 54.11, 53.01, 33.95. Purity: 99.3% by HPLC. HRMS (ESI):
+
calcd for (M+H) (C25
H
23
N
5
3
O ) 442.1874, found 442.1872.
5
.1.6.10 3-(2-(4-Methylpiperazin-1-yl)-propionamino)-7,8-dehydrorutaecarpine (10i)
The compound 8b was reacted with excess N-methyl piperazine following the general procedure to give the
1
desired product 10i as a yellow solid in 68% yield. H NMR (400 MHz, DMSO
3
): δ 12.68 (s, 1H), 10.47 (s,
1
7
3
1
1
4
H), 8.74 (d, J = 0.5 Hz, 1H), 8.62 (dd, J = 7.9, 3.0 Hz, 1H), 8.17 (d, J = 6.9 Hz, 1H), 8.08 (d, J = 8.4 Hz, 1H),
.90 – 7.79 (m, 2H), 7.71 – 7.67 (m, 1H), 7.54 – 7.47 (m, 1H), 7.30 (t, J = 7.9 Hz, 1H), 4.00 – 3.90 (m, 2H),
1
3
.60 – 3.47 (m, 4H), 3.23 – 3.10 (m, 4H), 2.97 – 2.87 (m, 2H), 1.23 (s, 3H); C NMR (101 MHz, DMSO): δ
70.32, 158.35, 143.58, 139.81, 139.04, 135.95, 129.49, 127.25, 126.86, 126.40, 121.87, 120.73, 120.42,
19.25, 117.59, 116.10, 114.74, 112.68, 107.98, 58.81, 55.84, 55.24, 54.68, 53.64, 52.27, 51.76, 50.13, 47.09,
5.96, 45.60, 45.51, 41.41, 40.40, 39.93, 39.31, 39.00, 36.20, 34.17, 31.01. Purity: 99.7% by HPLC. HRMS
+
(
ESI): calcd for (M+H) (C26
H
26
N
6
O
2
) 445.2190, found 445.2199.
5
.1.6.11 3-(2-Phenylamino-propionamino)-7,8-dehydrorutaecarpine (10k)
The compound 8b was reacted with excess aniline following the general procedure to give the desired product
1
1
0k as a yellow solid in 71% yield. H NMR (400 MHz, DMSO): δ 12.69 (s, 1H), 10.48 (s, 1H), 8.75 (s, 1H),
8.63 (d, J = 6.6 Hz, 1H), 8.17 (d, J = 7.6 Hz, 1H), 8.08 (d, J = 8.5 Hz, 1H), 7.85 (d, J = 7.8 Hz, 3H), 7.69 (d, J
=
8.1 Hz, 1H), 7.49 (t, J = 8.3 Hz, 2H), 7.37 – 7.22 (m, 2H), 7.09 (d, J = 3.7 Hz, 1H), 6.59 (dd, J = 36.5, 6.0
1
3
Hz, 1H), 3.94 (d, J = 3.6 Hz, 2H), 3.48 – 3.36 (m, 1H), 2.98 – 2.85 (m, 2H); C NMR (101 MHz, DMSO): δ
1
69.50, 164.76, 158.28, 148.10, 139.82, 135.56, 135.10, 129.28, 128.89, 127.48, 126.55, 121.79, 120.80,
20.46, 117.62, 116.58, 116.00, 115.34, 115.16, 112.68, 112.45, 108.08, 47.39, 43.54. Purity: 99.5% by
1
27

ACCEPTED MANUSCRIPT
-
HPLC. HRMS (ESI): calcd for (M-H) (C H N O ) 446.1622, found 446.1589.
27
21
5
2
5
.1.6.12 3-(2-N-Pyrrolyl-butyramino)-7,8-dehydrorutaecarpine (11f)
The compound 8c was reacted with excess pyrrolidine following the general procedure to give the desired
1
product 11f as a yellow solid in 67% yield. H NMR (400 MHz, DMSO): δ 12.65 (s, 1H), 10.51 (s, 1H), 8.71
(
d, J = 1.8 Hz, 1H), 8.62 (d, J = 7.5 Hz, 1H), 8.17 (d, J = 7.9 Hz, 1H), 8.06 (dd, J = 9.0, 2.2 Hz, 1H), 7.83 (t, J
8.2 Hz, 2H), 7.69 (d, J = 8.1 Hz, 1H), 7.49 (t, J = 7.6 Hz, 1H), 7.30 (t, J = 7.5 Hz, 1H), 2.71 – 2.63 (m, 2H),
=
13
2
.54 (d, J = 6.7 Hz, 2H), 2.42 (s, 4H), 1.61 – 1.49 (m, 4H), 1.42 (dd, J = 5.5, 5.1 Hz, 2H); C NMR (101 MHz,
DMSO): δ 170.44, 158.32, 143.54, 139.79, 138.99, 135.95, 129.48, 127.18, 126.84, 126.37, 121.85, 120.69,
120.38, 119.21, 117.55, 116.09, 114.66, 112.66, 107.95, 54.38, 53.63, 34.12, 25.61, 23.97. Purity: 99.4% by
-
HPLC. HRMS (ESI): calcd for (M-H) (C H N O ) 438.1935, found 438.1931.
26
25
5
2
5
.1.7 General procedures for the preparation of compounds 10m and 10n
The suspension of compound 10d or 10f (0.25 mmol) in thiocyclopentane-1 with excess iodomethane (0.5 mL)
was heated to 50 ºC and gradually transformed to a clear solution. The precipitation was formed after stirring
for 4h, cooled to 0 ºC and washed with ether. The resulting crude product was purified by recrystallization
from EtOH (15 mL) to afford 10m and 10n.
5
.1.7.1 3-(2-(N,N,N-Trimethyl)-propionamino)-7,8-dehydrorutaecarpine (10m)
The compound 10d was treated with iodomethane following the general procedure to give the desired product
1
1
0m as a yellow solid in 96% yield. H NMR (400 MHz, DMSO): δ 12.69 (s, 1H), 10.59 (s, 1H), 8.73 (s, 1H),
8.62 (dd, J = 7.4, 3.0 Hz, 1H), 8.18 (d, J = 8.0 Hz, 1H), 8.06 (d, J = 8.8 Hz, 1H), 7.86 (t, J = 9.4 Hz, 2H), 7.70
28