RSC Advances
Paper
0
0
(
3
dt, 1H, H6 , JHH 14.1, 3.1 Hz), 3.64 (ddd, 1H, H6 , JHH 13.9, 7.5, 30 min. Next the product was dissolved in anhydrous CH
2
Cl
2
(10
0 0
.8 Hz), 4.26 (d, 1H, H7 , J 15.8 Hz), 4.35–4.48 (m, 4H, H1 + mL) under argon and Pr NEt (230 mL, 1.32 mmol) was added
HH 2
H4 + H5 + H7 ), 4.73 (dd, 1H, H5 , J 12.2, 8.1 Hz), 5.42 (d, 1H, with exclusion of moisture. The solution was cooled and
H3 , J 5.3 Hz), 7.01 (s, 1H, H6 ), 7.24 (2d, 4H, Hortho-Me), 7.92 2-cyanoethoxy-N,N -diisopropylaminochlorophosphine (114 mL,
2d, 4H, Hortho-CO), 8.86 (br s, 1H, NH) ppm; C NMR (75.5 0.48 mmol) was added dropwise with a syringe. Aerwards, the
i
0
0
0
0
HH
0
0
0
HH
1
3
(
0
MHz, CDCl
3
): d 12.5 (CH
3
-C5), 21.9 (2CH
3
-Tol), 34.3 (C2 ), 41.2 solution was stirred at room temperature for 1 h. Then 15 mL of
0
0
0
0
0
0
(
(
(
1
(
C6 ), 50.7 (C7 ), 64.9 (C5 ), 77.4 (C3 ), 78.4 (C1 ), 83.6 (C4 ), 110.9 CH
C5), 126.9 (Cipso-CO), 127.1 (Cipso-CO), 129.3 (2Cortho-Me), 129.4 phase was washed with saturated aqueous NaCl (15 mL). Aer
2Cortho-Me), 129.8 (2Cortho-CO), 130.0 (2Cortho-CO), 141.1 (C6), drying the organic phase with MgSO
44.4 (2Cipso-Me), 151.1 (C2), 164.2 (C4), 166.3 (O]C-C7 ), 167.2 rated under reduced pressure and the product was puried by
C]O), 167.3 (C]O) ppm; HRMS (ESI , m/z): calcd for column chromatography. The column was packed with silica
C H N NaO [(M + Na) ]: 572.2003, found: 572.2001.
2
Cl
2
were added to the reaction mixture and the organic
4
, the solvent was evapo-
0
+
+
gel using a 10% Et N solution in EtOAc/hexane 1 : 1 and the
3
2
9
31
3
8
1,2-Dideoxy-1b-[N-(1-thyminylacetyl)aminomethyl]-D-ribose (4). gradient used was from EtOAc/hexane 1 : 1 to pure EtOAc. Aer
To a solution of 3 (20 mg, 0.04 mmol) in EtOH (0.4 mL) was added the chromatography, a white solid was obtained (198 mg, 85%
3
1
a solution of KOH (12 mg, 0.21 mmol) in EtOH–H
2
O (3 : 1) (0.08 yield). R
f
(EtOAc) ¼ 0.36 and 0.30. P NMR (162 MHz, Cl
3
):
9
P
9
P
+
mL). The completion of the reaction was reached at 30 min, d 148.02 and 147.92; HRMS (ESI , m/z): calcd for C43
a cation exchange resin (Dowex® 50WX8, hydrogen form) was [(M + H) ]: 816.3732, found: 816.3706; calcd for C43
added to the basic solution, in small increments, until neutrality [(M + Na) ]: 838.3551, found: 838.3527.
55 5
H N O
+
H
54
N
5
NaO
+
according to pH paper. The suspension was ltered of, and the
resin carefully washed with EtOH. The crude was subjected to (50 mg, 0.08 mmol) was dried by evaporation with anhydrous
column chromatography (5% MeOH/CH Cl
) to afford 4 as a white MeCN (ꢄ2) under reduced pressure and le in a desiccator for
solid in 95% yield. R : 0.1 (10% MeOH/CH Cl
KBr): n 3427, 2975, 2941, 2676, 1667, 1574, 1476 cm ; UV CH
DMT-T* hemisuccinate derivative (7). The DMT derivative 5
2
2
ꢀ
2
); mp: 133–135 C; IR 30 min. Once dried, the compound was dissolved in anhydrous
f
2
ꢁ1
(
(
2
Cl
2
(5 mL) under argon. Succinic anhydride (11 mg, 0.11
1
MeOH): l(max) ¼ 268 nm (3 3100); H NMR (300.13 MHz, MeOH- mmol) and DMAP (13 mg, 0.11 mmol) were added and the
0
0
d ): d 1.83 (m, 2H, H2 ), 1.88 (s, 3H, Me-C5), 3.38 (d, 2H, H6 , JHH solution was stirred overnight at room temperature. Then 15
4
0
0
4
1
4
.8 Hz), 3.53 (dd, 1H, H5 , J 11.7, 5.2 Hz), 3.60 (dd, 1H, H5 , J
mL of CH Cl were added and the solution was washed with
2 2
HH
0
HH
0
0
1.7, 4.2 Hz), 3.78 (q, 1H, H4 , J 4.3 Hz), 4.22 (m, 2H, H1 + H3 ), 0.1 M H NaPO and saturated aqueous NaCl (2 ꢄ 20 mL). The
HH
2
4
0
.40 (s, 2H, H7 ), 7.37 (d, 1H, H6, J 1.1 Hz) ppm; C NMR (75.5 organic layer was dried over anhydrous MgSO , ltered and
HH 4
13
0
0
0
MHz, MeOH-d
(
(
C
4
): d 12.2 (Me), 38.8 (C2 ), 44.1 (C6 ), 51.1 (C7 ), 63.7 evaporated to dryness. The resulting hemisuccinate 7 was ob-
0 0 0 0
C5 ), 73.7 (C3 ), 78.4 (C1 ), 88.7 (C4 ), 111.0 (C5), 143.7 (C6), 153.0 tained as a white solid (46 mg, 79% yield) and was used in the
0
+
C2), 167.0 (C4), 169.8 (O]C-C7 ) ppm; HRMS (ESI , m/z): calcd for next step without further purication.
R
f
(CH
2
Cl
2
/MeOH,
+
13
H
1
19
3
N NaO
6
[(M + Na) ]: 336.1166, found: 336.1166.
,2-Dideoxy-5-O-(4,4 -dimethoxytrityl)-1-[N-(1-thyminyla-
cetyl)aminomethyl]-D-ribose (5, DMT-T*). To a solution of 4,4 - DMT-T*. Preparation of (8). The hemisuccinate derivative 7
10 : 0.5) ¼ 0.20.
0
Functionalization of controlled pore glass with succinyl
0
dimethoxytrityl chloride (81.3 mg, 0.24 mmol) in anhydrous prepared above was incorporated on a long-chain alkylamine-
pyridine (0.8 mL) was added successively anhydrous Et N (46 controlled pore glass support (LCAA-CPG). Amino-LCAA-CPG
3
mL, 0.32 mmol) and 4 (50 mg, 0.16 mmol). The solution was (CPG New Jersey; 150 mg, 73 mmol amino per g) was placed
ꢀ
heated at 45 C during 5 h. The solvent was evaporated and the into a polypropylene syringe tted with a polypropylene disc
2 2
residue was puried by column chromatography (10% MeOH/ and washed sequentially with MeOH, CH Cl and MeCN
0
CH
MeOH/CH
2
Cl
2
) to afford 5 as a white solid in 69% yield. R
f
: 0.45 (10% (2 ꢄ 5 mL) and dried under vacuum. Then 2,2 -dithio-bis(5-
ꢀ
2
Cl
2
); mp: 107–109 C; IR (KBr): n 3540, 3473, 3415, nitropyridine) (DTNP) (20 mg, 0.06 mmol) dissolved in 200 mL
; H NMR (300.13 MHz, of a mixture of MeCN/CH Cl (1 : 3) was added to a solution of 7
2 2
MeOH-d ): d 1.77 (s, 3H, Me-C5), 1.84 (m, 2H, H2 ), 3.11 (d, 2H, (23 mg, 0.03 mmol) and DMAP (8 mg, 0.06 mmol) in MeCN (500
H5 , J 4.9 Hz), 3.29 (overlapped with MeOH-d , 1H, H6 ), 3.46 mL). Next, Ph P (17 mg, 0.06 mmol) was added. The mixture was
dd, 1H, H6 , JHH 14.0, 7.1 Hz), 3.74 (s, 6H, Me-DMT), 3.91 (m, vortexed for a few seconds and added to the support and
0 0 0 0
H, H4 ), 4.25 (m, 4H, H1 + H3 + 2H7 ), 6.84 (d, 4H, Harom, JHH allowed to react for 1 h. The support was washed with MeOH,
ꢁ1
1
2961, 2932, 1680, 1617, 1508 cm
0
4
0
0
HH
4
3
0
(
1
8
1
3
.9 Hz), 7.11 (s, 1H, H6), 7.14–7.50 (m, 9H, Harom); ppm;
C
CH
2
Cl
2
and MeCN (2 ꢄ 5 mL) and dried under vacuum. The
0
NMR (75.5 MHz, MeOH-d
4
): d 12.2 (CH
3
-C5), 39.1 (C2 ), 44.4 functionality of the resin was determined by DMT quantica-
0
0
0
0
0
ꢁ1
(C6 ), 51.0 (C7 ), 55.7 (2O-CH
3
), 65.7 (C5 ), 74.5 (C3 ), 78.5 (C1 ), tion (44.3 mmol g ). Finally, the solid support was treated with
7.4 (C-DMT), 87.7 (C4 ), 110.9 (C5), 114.1 (4CHarom), 127.8 a mixture of Ac O/DMF (1 : 1, 500 mL) during 30 min to cap free
0
8
2
(CHarom), 128.8 (2CHarom), 129.4 (2CHarom), 131.3 (4CHarom), amino groups.
1
1
C
37.3 (2Cipso), 143.6 (C6), 146.5 (Cipso), 152.9 (C2), 160.1 (2Cipso),
+
67.0 (C4), 169.5 (O]C-C7) ppm; HRMS (ESI , m/z): calcd for
+
Oligonucleotide synthesis and purication
34
H
37
N
3
NaO
8
[(M + Na) ]: 638.2473, found: 638.2474.
DMT-T* phosphoramidite derivative (6). Compound 5 Oligonucleotides used in this study are summarized in Table 1.
150 mg, 0.24 mmol) was dried by evaporation with anhydrous Modied oligonucleotides 15Mer_T*(01), (02) and (03) were
MeCN (ꢄ2) under reduced pressure and le in a desiccator for prepared on a DNA synthesizer (Applied Biosystems 3400,
(
9584 | RSC Adv., 2017, 7, 9579–9586
This journal is © The Royal Society of Chemistry 2017