Supporting Information for
“Improvement of cinchona alkaloids bonding crown ethers based chiral
stationary phases by chiral modification”
Jianchao Zhao 1, Haixia Wu 1, Dongqiang Wang 1, Haibo Wu 1, Lingping Chen 1, Yu Jin 1,
Yanxiong Ke 1,∗∗, Xinmiao Liang 1,2,*
1
Engineering Research Center of Pharmaceutical Process Chemistry, Ministry of
Education, School of Pharmacy, East China University of Science and Technology,
130 Meilong Road, Shanghai 200237, China
2
Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023,
China
Table of Content
1. Chemicals and equipment
S2
2. Preparation of CSP 1 ~ CSP 4
S3
3. 1HNMR
S8
4. LC-MS analysis results
S11
5. References
S18
s1
1. Chemicals and equipment.
Potassium hydroxide, potassium iodide, sodium carbonate, sodium borohydride,
thionyl
chloride,
pyridine,
N-methyl
imidazole,
azodiisobutyronitrileacetone,
ammonium hydroxide, chloroform, cobalt nitrate and toluene were purchased from
Shanghai Lingfeng Chemicals Co., Ltd. (China). Di-p-toluoyl tartaric acid (DTTA),
phenyl isocyanate were purchased from Shanghai Hanhong Chemicals Co., Ltd.
(China). Pentaethylene glycol, sodium perchlorate, 2,3-dihydroxybenzaldehyde,
chloroacetyl
chloride,
Acryloyl
chloride,
p-Toluenesulfonyl
chloride,
N,N-Diisopropylethylamine (DIEA), and 3,4-dihydroxybenzaldehyde were purchased
from Aladdin Reagent (shanghai) Co., Ltd. (China). 4-Nitrophenyl chloroformate and
3-Mercaptopropyltriethoxysilane were purchased from J&K Scientific., Ltd. (China).
Quinine (ee > 99.0%) and Quinidine (ee > 99.0%) were purchased from Daicel Chiral
Technologies (China) Co., Ltd.
Anhydrous ethanol, ethyl acetate, methanol, acetonitrile, tetrahydrofuran and
dichloromethane were purchased from Shanghai Heqi Chemicals Co., Ltd. (China).
HPLC-grade spherical silica gel (5 μm particle size; 10 nm pore size; 300 m2/g
surface area) was purchased from Acchrom Technologies Co., Ltd (China). HPLC
grade methanol, ethanol and acetonitrile were purchased from J&K Scientific., Ltd.
(China). Formic acid (FA), diethylamine (DEA), and lithium perchlorate were
purchased from Acros (USA). HPLC-grade water used in experiments was purified by
Milli-Q system (Millipore, Bedford, MA, USA).
Analytes were obtained from commercial suppliers.
All the chromatographic separations were performed on Waters HPLC system
consisting of a 515 HPLC pump, 7725i manual injector, model 1500 column heater,
and 2489 UV/Vis detector (Waters, USA). Quinine-crown ethers CSP columns were
used (5 μm, 150 mm × 4.6 mm, laboratory-made). 1HNMR identifications were
carried out on a Bruker AVANCE 400 (Germany) at a temperature of 25 ℃.
Elemental analysis (EA) was measured on an elementar vario EL III (Germany).
UPLC-ESI-LC/MS analysis was performed by Waters ACQUITY UPLCTM system
s2
with a Quattro Micro MS operating in ESI+ mode (Waters, USA). Separation was
carried out on ACQUITY UPLC BEH C8 column (1.7 μm, 50 mm × 2.1 mm i.d.)
(Waters, Ireland).
2. Preparation of CSP 1 ~ CSP 4
Fig. s1. Scheme of preparation of (1S, 2S)-2-aminocyclohexyl phenylcarbamate
Fig. s2. Scheme of the preparation of CSP 1 ~ CSP 4. (a) KOH, p-Toluenesulfonyl chloride,
THF, rt, 19 h. (b) Na2CO3, NaClO4, 2,3-dihydroxybenzaldehyde, ACN, reflux for 48 h. (c) (1S,
2S)- 2-aminocyclohexyl phenylcarbamate, EtOH, reflux for 4h (d) NaBH4, EtOH, rt, 24 h. (e)
Chloroacetyl chloride, Na2CO3, THF/H2O, 0 °C, 4 h. (f) NH3.H2O, KI, EtOH, 45 °C, 12 h. (g)
Toluene, rt, 12 h. (h) DCM, rt, 12h. (i) 3-mercaptopropylsilica gel, MeOH, AIBN, N2, reflux for
6h. (j) Acryloyl chloride, Na2CO3, THF/H2O, 0 °C, 4 h.
(1S, 2S)-2-aminocyclohexyl phenylcarbamate (Heca)
The synthesis procedure of Heca was corresponding to the method our group had
s3
developed [4]. Phenyl isocyanate (47.6 g, 400 mmol) was added to the mixture of
2-azidocyclohexan-1-ol (28.2 g, 200 mmol) and N-methyl imidazole (4.1 g, 50 mmol)
in anhydrous DCM (300 mL). The solution was allowed to stir at RT for about 36 h,
and then Co(NO3)2 (7.6 g) and NaBH4 (15 g) were added. For another 4 h, excess 6 M
HCl was added slowly to ensure the product in hydrochloride salt form. The aqueous
phase was washed with DCM, neutralized by NaOH and extracted with ethyl acetate
in turn. The organic phase was dried by anhydrous Na2SO4, and the crude racemic
product (23.8 g, yield: 50.8%) was obtained after removing the solvent in vacuo.
The above crude product was mixed with 1 eq. L-DTTA in solution of 200 mL ethyl
acetate. The resulting mixture was allowed to stand at RT until solid precipitated. The
collected solid (ee% = 90%) could mixed with slightly more (about 0.2 eq.) L-DTTA
and stirred in hot ethyl acetate. The collected solid could reach acceptable optical
purity (ee% = 96.2%). 1HNMR (CDCl3): δ 1.23-1.39 (m, 5H), 1.68-1.80 (m, 2H),
1.93-2.01 (m, 1H), 2.09-2.16 (m, 1H), 3.55-3.75 (m, 1H), 4.36-4.45 (m, 1H), 6.79 (s,
1H), 7.06 (t, 1H), 7.30 (t, 2H), 7.38 (d, 2H).
Compound C0 [1]
A mixture of 2,3-dihydroxybenzaldehyde (1.00 g,7.25 mmol), Na2CO3 (2.31 g,
21.75 mmol) and NaClO4 (1.02g, 7.25mmol) was taken in ACN (40 mL).
Pentaethyleneglycol di-p-toluenesulfonate (4.36 g, 7.98 mmol) was added to it with
stirring and the solution was refluxed for 48 h, and then the cooled mixture was
filtered. The filtrate was evaporated to dryness and the residue was extracted with
CH2Cl2 3 or 4 times. The extract was evaporated to yield a viscous oil that was was
purified by chromatography (DCM/MeOH, 100/1) to give the product as white solid.
Compound C0: white solid (40% yield), 1HNMR (DMSO-d6): δ 3.51-3.58 (d, 12H),
3.79-3.82 (d, 4H), 4.19 (s, 2H), 4.31 (s, 2H), 7.17 (t, 1H), 7.28 (d, 1H), 7.38 (d, 1H),
10.33 (s,1H). Lc-Ms: [M+H]+=341.05 (theoretical M=340.15).
Compound C1
Compound C0 (0.70 g, 2.06 mmol) and (1S, 2S)- 2-aminocyclohexyl
phenylcarbamate (0.50 g, 2.14 mmol) were dissolved in 30 ml EtOH and the solution
s4
was refluxed for 4 h. After cooling to room temperature, 10 equivalent NaBH4 was
added portionwise, and then the mixture was stirred for 48h at RT. The reaction was
quenched by addition of water, and then the solvent was removed under reduced
pressure. The residue was extracted with dichloromethane, and the organic extract
was dried with sodium sulfate, filtered, and concentrated under reduced pressure and
the crude product was obtained as light yellow oil. The crude product was purified
by chromatography (DCM/MeOH, 100/1) to give the product as white solid.
Compound C1: white solid (90% yield), 1HNMR (CDCl3): δ 1.17-1.33 (t, 4H),
1.68 (d, 2H), 2.11-2.20 (t, 2H), 2.56-2.67 (t, 2H), 3.59 (s, 2H), 3.60 (s, 5H),
3.66-3.74 (t, 7H), 3.84-3.87 (t, 3H), 3.90-3.99 (t, 2H), 4.08-4.10 (t, 2H), 4.25-4.27 (t,
2H), 4.46-4.51 (t, 1H), 6.77-6.84 (d, 2H), 6.90-6.99 (t, 2H), 7.22-7.26 (t, 2H), 7.44 (d,
2H), 7.85 (s, 1H). Lc-Ms: [M+H]+=559.56 (theoretical M= 558.29).
Compound C2
To a solution of the compound C1 (1.00g, 1.79 mmol), Na2CO3 (0.97 g, 9.00 mmol)
in 30 ml THF/H2O (v/v 1:1) at 0 oC and 1.1 equivalent chloroacetyl chloride was
added dropwise. And then the mixture was stirred for 4h at RT. The solvent was
removed under reduced pressure and some water was added. The aqueous phase was
extracted with dichloromethane, and the organic extract was dried with sodium
sulfate, filtered, and concentrated under reduced pressure. To a solution of crude
product and catalytic amount KI in 30 ml EtOH, and excess NH3.H2O was added.
And then the mixture was stirred for 12h at 45 oC. The solvent was removed under
reduced pressure and the residue was extracted with dichloromethane, and the
organic extract was dried with sodium sulfate, filtered, and concentrated under
reduced pressure to yield viscous oil that can be used directly in the next steps
without further purification.
Compound C3 [2]
Quinine/quinidine (1.00 g, 3.08 mmol) was dissolved in toluene (50 ml) and the
solution was dried by using Dean-Stark apparatus 2 h. After cooling to room
temperature, 4-nitrophenyl chloroformate (0.62 g, 3.08 mmol) was added portionwise,
s5
and then the mixture was stirred for overnight at RT. The mixture was filtered, and the
residue was washed by 150 ml n-hexane. Activated quinine (1.39g, 90%)/quinidine
(1.29, 84%) was obtained as a pale yellow solid which was used in the next step
without any other purification.
Compound C5
To a solution of the compound C4 (0.60g, 1.76 mmol), Na2CO3 (0.75 g, 7.04 mmol)
in 30 ml THF/H2O (v/v 1:1) at 0 oC and 1.1 equivalent chloroacetyl chloride was
added dropwise. And then the mixture was stirred for 4h at RT. The solvent was
removed under reduced pressure and some water was added. The aqueous phase was
extracted with dichloromethane, and the organic extract was dried with sodium sulfate,
filtered, and concentrated under reduced pressure, and then purified by column
chromatography on silica gel to obtain the product as a white solid (0.70g, 95%)
1
HNMR (CDCl3): δ 3.61-3.62(t,4H), 3.64-3.67(t,3H), 3.68(s,3H), 3.70-3.73(t,2H),
3.87(t,2H), 3.92(t,2H), 3.98(s,2H), 4.13(t,2H), 4.32(t,2H), 4.46(d,2H), 6.82(d,1H),
6.87(d,1H), 6.94(t,1H), 7.33(s,1H). LC-MS: [M+H]+=418.50 (theoretical M=417.16).
To the solution of the white product and catalytic amount KI in 30 ml EtOH, and
excess NH3.H2O was added. And then the mixture was stirred for 12h at 45 oC. The
solvent was removed under reduced pressure and the residue was extracted with
dichloromethane, and the organic extract was dried with sodium sulfate, filtered, and
concentrated under reduced pressure to yield crude product that can be used directly
in the next steps without further purification.
Synthesis of chiral selector compounds C6 ~ C8
To a solution of the compounds C2 in 30 ml DCM was added excess activated
quinine portionwise, and the mixture was stirring for overnight at rt. The solvent was
removed under reduced pressure and the residue was purified by column
chromatography on silica gel to obtain the product as a slight yellow solid.
compounds C6: slight yellow solid (0.5g), LC-MS: [M+H]+=966.80 (theoretical
M=965.48).
Compound C7: slight yellow solid (0.46g), LC-MS: [M+H]+=966.67 (theoretical
s6
M=965.48).
Compound C8: slight yellow solid (0.53g). LC-MS: [M+H]+=749.5 (theoretical
M=748.37)。
Synthesis of chiral selector compounds C9
To a solution of the compound C1 (0.70g, 1.26 mmol), Na2CO3 (0.53 g, 5.04 mmol)
in 30 ml THF/H2O (v/v 1:1) at 0 oC and 1.1 equivalent Acryloyl chloride was added
dropwise. And then the mixture was stirred for 4h at RT. The solvent was removed
under reduced pressure and some water was added. The aqueous phase was extracted
with dichloromethane, and the organic extract was dried with sodium sulfate, filtered,
and concentrated under reduced pressure, and then purified by column
chromatography on silica gel to obtain the product as a white solid.
Compound C9: white solid (0.47g, 60%). 1HNMR (CDCl3): δ 1.16-1.31(m,4H),
1.42(t,1H),
1.66-1.72(m,3H),
2.17(t,1H),
3.55-3.70(m,12H),
3.89-3.92(t,3H),
4.10-4.11(t,2H), 4.25-4.33(m,1H), 4.61-4.78(t,3H), 5.48-5.51(t,1H), 6.29(d,1H),
6.66-6.98(m,3H), 7.21-7.33(m,5H). LC-MS: [M+H]+=613.08 (theoretical M=612.30).
Preparation of 3-mercaptopropyl silica[3]
To the a suspension of silica gel (12.0 g) in 250 mL anhydrous toluene,
3-mercaptopropyltriethoxysilane (15 mL) and anhydrous pyridine (15 mL) were
added. The mixture refluxed for 48 h, and then was filtrated. The silica gel was
washed with methanol, DCM, CHCl3 and acetone respectively and then dried under
vacuum at 50 oC. About 13.0 g modified gel was obtained. (C 3.58%, H 1.05%,
0.67mmol/g).
Preparation of CSP 1 ~ CSP 4
To a suspension of thiol-modified silica gel (2.5 g) in MeOH (20 ml), comounds
C6~C9 and AIBN (50 mg) were added, respectively. The mixture was stirred under N2
reflux for 6 h. After cooling and filtration, the silica gel was washed with methanol,
DCM, CHCl3, acetone and dried in vacuo at 50 °C to yield CSP 1 ~ CSP 4.
Anal. Found: C 7.65%, H 1.49%, N 0.35% for CSP1 (0.125 mmol/g); C 6.83%, H
1.35%, N 0.24% for CSP2 (0.043 mmol/g); C 5.56%, H 1.33%, N 0.26% for CSP3
s7
(0.037 mmol/g); C 4.97%, H 1.22%, N 0.22% for CSP4 (0.031 mmol/g).
3.
1HNMR:
Compound C0
Compound C1
s8
Compound C6
Compound C7
s9
Compound C8
Compound C9
s10
4. LC-MS analysis results
131218
131229W D Q lin-guanm iquan
2: D iode Array
254
R ange: 6.75e-2
10.70
4.0e-2
AU
3.0e-2
2.0e-2
1.62
1.98
1.0e-2
8.02
0.0
Tim e
2.50
5.00
7.50
10.00
12.50
15.00
131218
131229W D Q lin-guanm iquan 604 (11.164)
1: S can E S +
9.68e7
358.07
%
100
0
341.05 359.27
363.05 502.22 599.33 788.13 899.34 966.12
323.03
200
400
600
800
m /z
1000
Compound C0
s11
140221
20140324-HuanJiAnChun-GuanmiZhongAn
11.13
4.0e-2
2: Diode Array
220
Range: 4.366e-2
AU
3.0e-2
2.0e-2
1.0e-2
3.50
1.63 1.97
0.0
Time
5.00
10.00
15.00
140221
2 0 1 4 0 3 2 4 -H u a n J iA n C h u n -G u a n m iZ h o n g A n 6 2 5 (1 1 .5 5 2 )
55 9.56
5 .7 4 e 6
%
100
56 0.6 0
23 5.32
0
200
36 5.30
400
56 1.7 1
6 86 .18
600
800
11 22 .6 6
1000
1200
13 80 .73
m /z
1400
Compound C1
s12
131229
140102W DQ-4linguanm ian
2: Diode Array
220
Range: 4.017e-1
1.68
3.0e-1
AU
2.5e-1
2.0e-1
1.5e-1
1.0e-1
5.0e-2
6.47
0.0
Tim e
5.00
10.00
15.00
131229
140102W D Q -4linguanm ian 111 (2.052)
1: S can E S +
9.28e7
342.25
%
100
222.18
343.32
564.32 684.33
0
200
400
600
847.23 888.26
800
m /z
1000
Compound C4
s13
140221
20140325 W DQ4
2: Diode Array
220
Range: 3.816e-2
8.42
3.5e-2
3.0e-2
2.5e-2
AU
2.0e-2
2.23
1.5e-2
1.0e-2
1.80
5.0e-3
6.57
4.20
0.0
Tim e
5.00
10.00
15.00
140221
20 14 032 5 W D Q 4 48 2 (8.90 9)
1: S c an E S +
1.08 e7
4 8 4.2 5
%
1 00
4 1 5 .5 5
4 9 5 .1 7
21 4 .2 5
0
200
6 1 6 .5 4
400
60 0
80 0
9 6 6 .8 0 1 0 1 8 .70
1 000
1 200
1 4 5 4 .8 2
m /z
1 400
Compound C6
s14
140221
20140403KuiNingDing-HuanJIAnChun-GuanMi
2: Diode Array
220
Range: 2.939e-2
7.48
2.22
2.5e-2
AU
2.0e-2
1.5e-2
2.70
1.0e-2
1.80
5.0e-3
1.48
3.98
0.0
Tim e
2.50
5.00
7.50
10.00
12.50
15.00
140221
2 0 1 4 0 4 0 3 K u iN in g D in g -H u a n J IA n C h u n -G u a n M i 4 3 4 (8 .0 2 2 )
4 1 5 .6 8
%
100
1: S can E S+
7 .7 5 e 6
4 1 6 .5 9
2 1 4 .2 5
0
200
5 0 6 .6 0
400
600
6 4 3 .6 3
800
9 6 6 .6 7 1 0 1 1 .4 9 1 1 9 4 .5 6
1000
1200
1 4 8 3 .5 4
m /z
1400
Compound C7
s15
140221
W DQ -G U AN MIAN -XIA NH UA -KU IN ING
2: D iode Array
254
R ange: 2.254e-1
4.92
1.6e-1
1.4e-1
1.2e-1
AU
1.0e-1
8.0e-2
6.0e-2
4.0e-2
2.0e-2
2.13
1.57
0.0
T im e
1.00
2.00
3.00
4.00
5.00
6.00
7.00
140221
W D Q -G U A N M IA N -X IA N H U A -K U IN IN G 2 9 7 (5 .4 9 3 )
1: S can E S +
1 .2 4 e 8
3 7 5 .4
%
100
2 8 6 .9
0
3 8 6 .5
2 1 4 .1
200
5 7 2 .5
400
600
7 4 9 .5
7 8 7 .4 9 9 4 .7
800
1 0 9 2 .3
1000
1 5 0 4 .7
1 5 9 5 .7 1 7 6 0 .5
m /z
1200
1400
1600
Compound C8
s16
140221
W DQ20141115-612
2: Diode Array
254
Range: 4.537e-1
5.20
4.0e-1
2.0e-1
AU
-3.125e-8
-2.0e-1
-4.0e-1
-6.0e-1
-8.0e-1
-1.0
Time
1.00
2.00
3.00
4.00
5.00
6.00
7.00
140221
W DQ20141115-612 297 (5.494)
1: Scan ES+
2.63e7
630.13
100
%
476.04
613.08
0
213.84 356.10
200
400
631.15
477.13
635.09
478.08
636.11
557.03
600
637.47
937.96 1087.16 1243.95
800
1000
1200
1427.00
1400
1678.10
m/z
1600
Compound C9
s17
5. References
[1] D'Souza, F., Chitta, R., Gadde, S., McCarty, A. L., Karr, P. A., Zandler, M. E., Sandanayaka, A.S.D.,
Araki, Y., Ito, O., J. Phys. Chem. B 2006, 110, 5905-5913.
[2] Franco, P., Lämmerhofer, M., Klaus, P. M., Lindner, W., J. Chromatogr. A 2000, 869, 111-127.
[3] Keunchkarian, S., Padró, J. M., Gotta, J., Nardillo, A. M., Castells, C. B., J. Chromatogr. A 2011, 1218,
3660-3668.
[4] Wu, H., Su, X., Li, K., Yu, H., Ke, Y., Liang, X., J. Chromatogr. A 2012, 1265, 181-185.
s18