Quinazoline is a potential class in the design of synthetic anti-cancer
drugs according to the kinase enzyme inhibition mechanism [1-4]. Gefitinib
(Iressa), erlotinib (Tarceva), lapatinib (Tykerb) and vandetanib (Caprelsa)
are typical quinazoline compounds that have been introduced into the
production of cancer drugs. Among them Gefitinib and Erlotinib are the first
epidermal growth factor receptor(EGFR) chemotherapy drugs used to treat
non-small cell lung cancer. Erlotinb is a derivative of quinazoline with the
trade name Tarceva, produced by Hoffmann pharmaceutical company - La
Roche. The drug is highly effective for the treatment of non-small cell lung
cancer (NSCLC) with EGFR activating mutation. This is a breakthrough
method in treating NSCLC that creates an opportunity to prolong life time
with higher quality of life. In Vietnam, erlotinib hydrochloride Tarceva drug
has not been widely used; first of all because the cost of treatment with
Tarceva is very high, 2,000 USD per treatment cycle (one cycle = 1 month), price
in Vietnam market is about 42 million VND per bottle of 30 150mg tablets.
Therefore, the thesis "Research on synthesis and evaluation of cytotoxic
activity of quinazoline compounds" is a scientifically and practically
significant research direction.
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1
VIETNAM ACADEMY OF SCIENCE AND
TECHNOLOGY
INSTITUTE OF CHEMISTRY
------------------
RESEARCH ON THE SYNTHESIS AND EVALUATION
OF CYTOTOXIC ACTIVITY OF QUINAZOLINE
COMPOUNDS
Speciality : Organic Chemistry
Code : 9.44.27.01
Students : Đinh Thuy Van
DISSERTATION SUMMARY
Ha Noi – 2019
2
The work was completed at the Vietnam academy of Science
and Technology
Supervisors:
Supervisor 1: Pro.Doc. Nguyen Van Tuyen
Supervisor 2: Doc. Dang Thi Tuyet Anh
Reviewer 1:
Reviewer 2:
Reviewer 3:
The thesis will be defended before the Doctoral Dissertation Council,
at the Academy of Science and Technology - Vietnam Academy of
Science and Technology. No. 18 - Hoang Quoc Viet, Cau Giay,
Hanoi. At ... time ... .. 2019
1
A. INTRODUCTION
1. The urgency, scientific and practical significance of the thesis
Quinazoline is a potential class in the design of synthetic anti-cancer
drugs according to the kinase enzyme inhibition mechanism [1-4]. Gefitinib
(Iressa), erlotinib (Tarceva), lapatinib (Tykerb) and vandetanib (Caprelsa)
are typical quinazoline compounds that have been introduced into the
production of cancer drugs. Among them Gefitinib and Erlotinib are the first
epidermal growth factor receptor(EGFR) chemotherapy drugs used to treat
non-small cell lung cancer. Erlotinb is a derivative of quinazoline with the
trade name Tarceva, produced by Hoffmann pharmaceutical company - La
Roche. The drug is highly effective for the treatment of non-small cell lung
cancer (NSCLC) with EGFR activating mutation. This is a breakthrough
method in treating NSCLC that creates an opportunity to prolong life time
with higher quality of life. In Vietnam, erlotinib hydrochloride Tarceva drug
has not been widely used; first of all because the cost of treatment with
Tarceva is very high, 2,000 USD per treatment cycle (one cycle = 1 month), price
in Vietnam market is about 42 million VND per bottle of 30 150mg tablets.
Therefore, the thesis "Research on synthesis and evaluation of cytotoxic
activity of quinazoline compounds" is a scientifically and practically
significant research direction.
2. Objectives of the dissertation
1. Research to improve the synthesis process of erlotinib hydrochloride drugs.
2. Research on the synthesis and determination of quinazoline derivative structure.
3. Research on the synthesis and determination of the structure of hybrid
compounds of quinazoline derivatives and azides via triazole bridges.
2
4. Research on cytotoxic activity of hybrid compounds synthesized on three
human cancer cell lines including KB (carcinoma, Hep-G2 (liver cancer) and
Lu (non-small cell lung cancer).
3. New points of the dissertation
a. Successfully synthesized erlotinib hidrocloride according to the new
improvement process
b. Synthesis of 23 new quinazoline derivatives in which there were 19
derivatives containing triazole rings:
* 4 derivatives of erlotinib and different azides via triazole bridges
* 4 derivatives of quinazoline-4- amine containing crown ether group in
position C-6, C-7 following a completely new path. These derivatives are used to
hybridize with other active azides via triazole bridges by click reaction.
* 15 hybrid compounds of quinazoline crown ether and azides via triazole bridges
c. The structure of new hybrid compounds has been confirmed from the
results of analysis of infrared spectral data (IR), nuclear magnetic resonance
spectroscopy (
1
H-NMR and
13
C-NMR, HMBC, HSQC) and mass
spectroscopy (HRMS).
d. Evaluation of activity of 19 new quinazoline derivatives on three human
cancer cell lines including KB (carcinoma, Hep-G2 (liver cancer) and Lu
(non-small cell lung cancer) in which there are 13 substances that can cause
investigated cancer cell toxicity. Among them there are 8 substances exhibiting
strong anti-cancer cell activity with the value of IC50 from 2 to 6 µM.
e. Using protein docking simulation to predict the target activity of
compounds 120d, 122a, 122b, 123c
f. Synthesized Compound 122a which has the strongest inhibitory activity
for all three KB cell lines, Hep-G2 and Lu with IC50 values of 0.04 µM, 0.14
µM and 1.03 µM, respectively, 100 times higher than erlotinib. The 123c
compound has IC50 value (1.49; 1.61; 1.81 µM) equivalent to the Ellipticine
standard (IC50 is 1.95; 2.72; 1.38 µM, respectively).
3
4. Structure of the dissertation
The dissertation consists of 129 pages including:
Introduction: 2 pages.
Chapter 1. Literature review: 31 pages
Chapter 2. Experiment: 25 pages.
Chapter 3. Results and discussion: 56 pages.
The reference section has 122 documents on the relevant areas of the
dissertation, updated to 2018.
The appendix consists of 62 pages, including the spectroscopy of
synthesized substances.
5. Research methodology
The substances were synthesized according to known modern organic
synthesis methods, improved and applied appropriately in specific cases.
Reaction products were cleaned by column chromatography and
recrystallization. The structure of the product was determined by modern
spectral methods such as IR, HRMS, ESI-MS, 1H-NMR,
13
C-NMR,
HMBC, HSQC, DEPT. Biological activity was explored according to the
method of Mossman on three cancer cell lines, KB, Hep-G2 and Lu.
Protein docking simulation was used to predict the target activity of
synthesized compounds.
B. CONTENTS OF THE DISSERTATION
CHAPTER 1. LITERATURE REVIEW
This chapter presents the following contents:
- The quinazoline synthesis methods
- The erlotinib synthesis methods
- Anti-cancer activity of quinazoline derivatives
- Click reaction
- Protein docking technique
4
CHAPTER 2. EXPERIMENT
The experiment section consists of 25 pages, detailing the research methods,
synthesis process, refining process, physical properties of received products
such as melting point, shape, color, reaction performance and detailed data
of IR, HRMS, 1H-NMR, 13C-NMR, HMBC, HSQC, DEPT.
CHAPTER 3: RESULTS AND DISCUSSION
3.1. OBJECTIVES OF THE DISSERTATION
This dissertation focused on the development of an optimal procedure for
erlotinib hydrochloride synthesis (diagram 3.1) to produce a synthesis
process of erlotinib hydrochloride that can be applied into production in
Vietnam, synthesizing new quinazoline derivatives (diagram 3.2) and hybrid
compounds of quinazoline frame and triazole group (diagram 3.3) to search
for new compounds with interesting biological activity.
Diagram 3.1: Synthesis process of erlotinib hydrochloride (93)
(a) BrCH2CH2OCH3, K2CO3, Bu4NHSO4, DMF, 110°C; (b) H2O, CH3OH, KOH, 30
oC; (c)
Urea, 210-220°C; (d) P2O5, xylene, Reflux; (e) HNO3, acid acetic ice, 0°C; (f) Na2S2O4, H2O,
HCl; (g) DMF-DMA, acid acetic, toluen, 105°C; (h) 3-ethynylaniline, acid acetic, toluen, 60-
110oC; (i) HCl gas, CH3OH, 15-20°C.
5
Diagram 3.2: Synthesis of quinazoline derivatives containing crown
ether group in position C-6, C-7
Reagents and conditions: (a) NH2OH.HCl, NaOH, MeOH, H2O, mix, 30-60 minutes, 95-98%;
(b) Ac2O, reflux, 8-12 h, 90-95%; (c) Na2S2O4, H2O, 50-65
oC, 3-4 h, 80-85%; (d) 1,2-
dicloethan, or 1,3-dibrompropan, K2CO3, Bu4NHSO4, acetone, reflux, 10 h; (e) H2O, MeOH,
KOH, 30oC, 4 h; (f) Urea, 150-160 °C, 5 h; (g) P2O5, xylene, reflux, 5 h; (h) HNO3, acid
acetic ice, 0°C, 2 h (i) DMF-DMA, acid acetic, toluene, reflux, 4-6 h; (k) 3-etynylaniline,
acid acetic, toluene, 60oC-110oC, 4-6 h, 50-63%.
Diagram 3.3: Synthesis of hybrid compounds of quinazoline 119a-d
derivatives and azides via triazole bridges.
Reagents and conditions: 1 equiv 4-anilinoquinazoline 119a-d, 1,1 azide equiv, 12 equiv
DIPEA, 0,2 equiv CuI, THF, rt, 1-2 days, 70-90%.
6
3.2. SYNTHESIS OF ERLOTINIB HYDROCLORIDE
From the synthesis methods of erlotinib hydrochloride mentioned in the
reference as described in the diagrams 1.15-1.23 and the initial research
results of the authors, it was found that each method has its advantages and
disadvantages. The two biggest difficulties of the methods are the reduction
of the nitro group into the amino group and the 4-chloroquinazoline
intermediate synthesis reaction. In order to choose a path of synthesis of this
drug in accordance with the conditions in Vietnam, we carefully studied the
advantages and disadvantages of each method combined with the initial
research, we chose an appropriate method to study and improve the synthesis
of erlotinib hydrochloride as shown in diagram 3.1.
Product 93 was structured by modern spectral methods
1
H-NMR,
13
C-
NMR. Erlotinib hydrocloride 93 is a yellow solid with the melting point 228-
229
o
C. IR 3277, 3053, 3021, 2922, 2896, 2820, 2745, 2710, 1667, 1564,
1510, 1446, 1284, 1122, 8920 cm
-1
.
1
H-NMR (DMSO-d6) 11,45 (s, 1H,
NH); 8,81 (s, 1H, H-Ar); 8,30 (s, 1H, H-Ar); 7,90-7,72 (m, 2H, H-Ar); 7,53-
7,33 (m, 3H, HAr); 4,45-4,25 (m, 4H, CH2O); 3,79-3,70 (m, 4H, CH2O),
3,40 (s, 1H, C≡CH), 3,25 (s, 6H, OCH3).
13
C-NMR (DMSO-d6) 170,2;
159,1; 155,1; 151,2; 147,3; 142,3; 130,9; 125,8; 124,0; 122,3; 117,65; 114,2;
108,8; 100,9; 87,1; 80,6; 76,7; 73,5; 51,3.
3.3. SYNTHESIS OF HIBRID COMPOUNDS OF ERLOTINB-TRIAZOLE
The synthesis of hybrid structured compounds between two or more
bioactive substances is also a very interesting and new issue, now attracting
attention of many scientists. Synthesis of a hybrid compound from two
compounds with antitumor activity, especially those that act according to
7
different mechanisms of action, may increase activity or improve the
disadvantages of the original compounds. On the other hand, the hybrid
structured compounds when introduced into the body will be gradually
hydrolyzed by the enzymes in the body to produce the original substance,
thus reducing the side effects and increasing efficiency due to the long half-
life . In order to find and expand interesting new activities of erlotinib
derivatives, we studied and synthesized the hybrid compounds of erlotinib
and azides via triazole bridges with click reaction. Results were 4 new
derivatives which were 105a-d.
O
O
CH3
O
O
CH3
N
N
NH
N
N
N
CF
3
CN
O
O
CH3
O
O
CH3
N
N
NH
N
N
N
O2N
O
O
CH3
O
O
CH3
N
N
NH
N
N
N
NO
2
O
O
CH3
O
O
CH3
N
N
NH
N
N
N
NO
2
1240C, 75%
1210C, 83%
1020C, 86% 140
0C, 90%
105a
105b
105d105c
Figure 3.19: Chemical structure and some physical characteristics of
compounds 105a-d
The expected structure of hybrid compounds 105a-d is confirmed by their
IR, MS,
1
H-NMR and
13
C-NMR spectral data.
8
6,7-Bis(2-methoxyethoxy)-N-(3-(1-(3-nitro-phenyl)-1H-1,2,3-triazol-4-
yl)phenyl) quinazoline-4-amine 109b
O
O
CH3
O
O
CH3
N
N
NH
N
N
N
NO
2
Colorless solid. MP 121
o
C. Yield 83%.
IR (KBr) cm
-1
: 2930, 1623, 1583, 1535, 1507, 1442, 1350, 1238, 1034, 928.
1
H-NMR (DMSO-d6, 500 MHz) δ: 9.61 (1H, s, NH), 9.56 (1H, s), 8.81 (1H,
t, J = 2 Hz), 8.51-8.47 (2H, m), 8.40 (1H, s), 8.35-8.33 (1H, m), 7.95-7.92
(3H, m), 7.67 (1H, d, J = 5.5 Hz), 7.53 (1H, t, J = 8 Hz), 7.23 (1H, s), 4.33-
4.28 (4H, m, CH3OCH2CH2O), 3.81-3.75 (4H, m, CH3OCH2CH2O), 3.38
(3H, s, OCH3), 3.36 (3H, s, OCH3).
13
C-NMR (DMSO-d6, 125 MHz) δ:
156.4, 153.6, 152.9, 148.6, 148.1, 147.7, 140.2, 137.2, 131.6, 103.2, 129.2,
125.9, 123.1, 122.4, 120.6, 120.1, 119.1, 114.6, 108.2, 103.3, 70.1, 70.0,
68.4, 68.1, 58.4, 58.3. LC-MS/MS (m/z) Calc. for: C28H28N7O6: 558.2023
[M+H]
+
, found: 558.2061.
3.4. SYNTHESIS OF HIBRID COMPOUDS OF QUINAZOLINE
DERIVATIVES CONTAINING CROWN ETHER GROUP IN
POSITION C-6, C-7.
Studies on the relationship between structure and biological activity
(SAR) of EGFR inhibitors showed that the 4-anilinoquinazoline frame is
important for EGFR inhibitory activity, and substituents at the position C-6
and C-7 mainly contributing to their physical and chemical properties with
good compatibility with bulky branches [15,16,104,105]. With these
advantages, in recent years, many 4-anilinoquinazoline derivatives have been
designed and synthesized consecutively. Among them, anilinoquinazoline
9
analogues are combined with new tyfin EGFR inhibitors [17,106,107]. The
SAR shows that oxygen-containing heterocyclic rings with 12 members
higher ring size are fused anilinoquinazoline, and the preferred substituents
on 4-anilino is a halogen such as chlorine, bromine, or phenyl group in the
meta position [17,107]. Some of them have been proved to be active in
EGFR-mediated phosphorylated assays in human tumor cells A431 [17]
while another showed strong activity against dissociation by inhibition of
both tyrosine kinase receptors including EGFR, VEGFR, PDGFR, and
nonreceptor TKs includes C-Src and Abl kinase with higher inhibitory
activity against EGFR [107]. According to the results mentioned above, and
from erlotinib, we devised and synthesized the series of quinazoline
incorporating dioxygenated rings containing the ethynyl group in the meta
position of aniline without rings, for the purpose of collecting the agent
showing stronger anti-cancer activities.
In this study, the synthesis of quinazoline 119a-d crown ether through 5-6
steps with two different paths. One is from different benzaldehydes, two is
from acid 106 3.4- dihidroxy benzoic as described in diagram 3.14.
The fusion of quinazoline derivatives is showed in diagram 3.2
The results were 4 quinazoline derivatives containing crown ether group at
position C-6, C-7
10
Figure 3.26: Structure of 4 4-aminoquinazoline compounds containing
crown ether group at position C-6, C-7 119a-d.
The structure of compounds 119a-d was determined simply based on spectral
data analysis, including IR and
1
H-NMR, HRMS.
3.5. SYNTHESIS OF HIBRID COMPOUNDS OF QUINAZOLINE-
TRIAZOLE
The synthesis of hybrid compounds of 4-anilinoquinazoline and azides
via triazole bridge, the results were a number of new hibrid compounds with
3 components. 4-anilinoquinazoline was the skeleton, triazole cycle and aryl
were chained with variable substituents. Most EGFR-tyrosine kinase
inhibitors have the same set of 4-anilinoquinazoline, only substituents and
side chains changed. Therefore, the replacement of the acetylene moiety at
the C3 position of the phenyl ring by a triazole nucleus could rigid the
structure of the nucleus. Thus hydrogen bond between triazole ring and
peptide backbone of EGFR receptors could afford specifc conformations,
thereby improving inhibitory activities of hybrid compounds. Besides, with
respect to the triazolyl substituent, we consider their influence on bioactive
function including nitrophenyl and cyanotrifluoromethylphenyl. Due to the
11
specifc chemical and physical properties of nitrogen and fluorine, the
introduction of a NO2, CF3, and CN moieties in pharmacologically active
compounds is known to convey beneficial biological effects to the resulting
molecules. Hence organic and medicinal chemists are increasingly interested
in polyfunctional NO2–, CF3-, and CNsubstituted scaffolds. In that respect,
copper(I)-catalyzed azide alkyne cycloaddition (CuAAC) 119a-d with
nitrophenyl- and cyanotrifluoromethylphenylazides generating the target 4-
anilinoquinazoline–substituted triazole hybrid compounds 120–123a-d in
70–90% yields (diagram 3.3). The structure of hybrid compounds 11–14 was
determined by their
1
H NMR,
13
C NMR, and MS (ESI) spectroscopy.
Notably, the
1
H NMR spectroscopy showed a pic singlet at 9.17–9.65 ppm
corresponding to the triazolyl proton, while the
13
C NMR spectroscopy
showed peaks at 120–123 ppm and 147–149 ppm corresponding to
characteristics CH and Cq of the triazole core unit.
Synthesis reaction of hybrid compounds according to diagram 3.3
The obtained results were 4 ranges of hybrid compounds of compounds 119a-d
3.5.1. Synthesis of hybrid compounds of derivatives 119a
Hybrid compounds of 120a-d are all colorless crystals. MP: 186-267
o
C.
Yield 72%-90%.
120a, 212
o
C, 87%
120b, 242-243
o
C, 87%.
12
120c, 267
o
C. 72%
120d, 186
o
C, 90%
Figure 3.32: Chemical structure and physical characteristics of hybrid
compounds 120a-d
The structure of compound 120a was proved by IR, NMR spectroscopy.
N-(3-(1-(2-nitrophenyl)-1H-1,2,3-triazol-4-yl)phenyl)quinazolin-4-amine (120a)
Colorless solid. MP: 212
o
C. Yield 87%. IR (KBr) 3132, 2924, 2853,
1611, 1568, 1538, 1492, 1411, 1354, 1033, 924, 888, 773 cm
-1
.
1
H-NMR
(DMSO-d6, 500 MHz) δ 9.96 (1H, s, NH), 9.19 (1H, s), 8.65 (1H, s), 8.62
(1H, d, J = 8 Hz), 8.50 (1H, t, J = 1.5 Hz), 8.26 (1H, d, J = 7.5 Hz), 8.03-
7.95 (3H, m), 7.88 (2H, t, J = 7 Hz), 7.82 (1H, d, J = 7.5 Hz), 7.68-7.65 (2H,
m), 7.54 (1H, t, J = 8 Hz).
13
C-NMR (DMSO-d6, 125 MHz) δ 157.9, 154.5,
149.7, 147.1, 144.1, 139.9, 134.5, 133.1, 131.3, 130.2, 129.3, 129.1, 127.8,
127.5, 126.4, 125.6, 123.0, 122.9, 122.5, 121.0, 119.3, 115.2. ESI-MS (m/z)
Calc. for: C22H16N7O2: 410.1287 [M+H]
+
; Found: 410.3196.
The structure of substances 120b-d was similarly demonstrated to compound
120a by IR, NMR, and MS spectroscopy.
3.5.2. Synthesis of hybrid compounds of derivative 119b
13
121a 121b
121c 121d
Structure of hybrid compounds of substance 119b
The structure of hybrid compound 121d was proved by IR, NMR, HSQC,
HMBC, DEPT, MS spectra.
5-(4-(3-([1,3]Dioxolo[4,5-g]quinazolin-8-ylamino)phenyl)-1H-1,2,3-
triazol-1-yl)-2-(trifluoro-methyl)benzonitrile (121d)
Light yellow solid. MP: 256-257
o
C. Yield 90%.
IR (KBr) 3282, 3132, 2238 (CN), 1615, 1580, 1529, 1493, 1470,
1439, 1386, 1315, 1271, 1242, 1217, 1183, 1135, 1030, 911, 845, 790, 688
cm
-1
.
1
H-NMR (DMSO-d6, 500 MHz) δ 9.60 (1H, s, H-triazole), 9.53 (1H, s,
NH), 8.59 (1H, s, H-19), 8.54 (1H, d, J = 8.5 Hz, H-23), 8.49 (1H, s, H-2),
8.47 (2H, m, H-11, H-22), 8.14 (1H, s, H-5), 7.93 (1H, d, J = 8 Hz, H-15),
7.63 (1H, d, J = 7.5 Hz, H-13), 7.52 (1H, t, J = 8 Hz, H-14), 7.19 (1H, s, H-
9), 6.25 (2H, s, OCH2).
13
C-NMR (DMSO-d6, 125 MHz) δ 156.9 (C-4),
153.0 (C-2), 152.4 (C-6), 148.6 (C-9a), 148.0 (C-16), 147.3 (C-8), 140.3 (C-
14
10), 139.7 (C-18), 137.5 (C-22), 132.7 (q, J = 32.5 Hz, C-21), 129.8 (C-12),
129.2 (C-14), 123.7 (C-23), 122.2 (C-15), 120.4 (C-13), 120.2 (C-17), 118.9
(C-11), 1181 (C-19), 115.0 (C≡N), 110.2 (C-4a), 107.7 (C-20), 104.6 (C-9),
102.3 (C-7), 98.9 (C-5). HRMS calc. for : C25H15F3N7O2: 502.1161 [M+H]
+
;
Found: 502.1233.
The structure of substances 121a-c was proved similarly to 121d by
IR, NMR, MS spectra.
3.5.3 Synthesis of hybrid compounds of derivative 119c
The synthesized results of hybrid compounds of compound 119c were 4
hybrid compounds 122a-d
The structure of compound 122a was proved by IR, NMR, HSQC, HMBC,
DEPT, MS spectra.
N-(3-(1-(2-nitrophenyl)-1H-1,2,3-triazol-4-yl)phenyl)-7,8-dihydro [1,4]
dioxino [2,3-g] quinazolin-4-amine (122a)
Light yellow solid. Yield: 80%. MP: 195
o
C.
IR (KBr) 3134, 1603, 1568, 1531, 1505, 1415, 1348, 1289, 1220,
1066, 901 cm
-1
.
1
H-NMR (DMSO-d6, 500 MHz) δ 9.67 (1H, br.s, NH), 9.17
(1H, s), 8.49 (2H, s), 8.26 (1H, d, J = 8 Hz), 8.14 (1H, s), 8.02-7.97 (2H, m),
7.95 (1H, d, J = 8 Hz), 7.88 (1H, t, J = 8 Hz), 7.63 (1H, d, J = 7.5 Hz), 7.51
(1H, t, J = 8 Hz), 7.19 (1H, s), 4.42 (4H, d, J = 3.5 Hz, OCH2).
13
C-NMR
(DMSO-d6, 125 MHz) δ 156.7, 152.9, 149.2, 147.1, 145.7, 144.1, 143.7,
140.2, 134.5, 131.3, 130.1, 129.2, 129.1, 127.5, 125.6, 122.8, 122.1, 120.6,
15
118.9, 112.3, 110.0, 108.5, 64.5, 64.2. HRMS (ESI+) m/z calc. for:
C24H18N7O4 [M+H]
+
468.1342, Found: 468.1416.
The structure of the remaining compounds is proved by IR, NMR, MS spectra.
3.5.4 Synthesis of hybri