* All experimental methods are cited from the reference, please refer to the original source for details. We do not guarantee the accuracy of the content in the reference.
With toluene-4-sulfonic acid In N,N-dimethyl-formamide for 24 h; Inert atmosphere
To a solution of Inosine (0.998 g, 3.72 mmoli) in DMF (30 ml) were added 2,2-Dimethxypropane(1.8 mL, 14.59 mmoli) and p-Toluensulfonic acid monohydrate (0.038g, 0.372 mmoli). The reaction mixture was stirred under Ar for 24 h. After the evaporation of DMF, the reaction was basified with a solution of NH3 3percent and the evaporated to dryness. The residue obtained was purified by chromatography over silica gel (eluent: CH2Cl2/MeOH 95/5 v/v) to afford desiderated compound 22 as white foam (yield 80percent). 1H-NMR (200MHz, DMSO-d6) d: 1.34,1.50 (6H, s, (CH3)2C), 3.6 (2H, t, CH2-5'), 4.37 (1H, m, H-4'), 4.94 (1H, m, H-3'), 5.18 (1H, t, OH 5'), 5.37 (1H, dd, J=3.7, H-2',), 6.12 (1H, d, J=2.4, H-1'), 8.05 (1H, s, H-2), 8.32 (1H, s, H-8), 12.44 (1H, br s, NH-3). ESI MS: m/z 309.1 Da [M+H]+, C13H16N4O5 Mol. Wt. 308.29.
Reference:
[1] European Journal of Medicinal Chemistry, 2012, vol. 54, p. 202 - 209
[2] Journal of Medicinal Chemistry, 2018, vol. 61, # 5, p. 2087 - 2103
[3] Journal of Medicinal Chemistry, 2008, vol. 51, # 17, p. 5349 - 5370
[4] Heterocycles, 2013, vol. 87, # 11, p. 2369 - 2384
[5] Chinese Chemical Letters, 2011, vol. 22, # 12, p. 1439 - 1442
[6] Journal of Medicinal Chemistry, 2007, vol. 50, # 4, p. 782 - 793
2
[ 58-63-9 ]
[ 67-64-1 ]
[ 2140-11-6 ]
Reference:
[1] Tetrahedron, 2009, vol. 65, # 27, p. 5228 - 5239
[2] Nucleosides, Nucleotides and Nucleic Acids, 2005, vol. 24, # 5-7, p. 881 - 885
[3] Chinese Chemical Letters, 2014, vol. 25, # 12, p. 1583 - 1585
Reference:
[1] Chemistry - A European Journal, 2015, vol. 21, # 38, p. 13401 - 13419
12
[ 108-24-7 ]
[ 58-63-9 ]
[ 3181-38-2 ]
Yield
Reaction Conditions
Operation in experiment
82%
With dmap; triethylamine In acetonitrile at 20℃; for 1 h;
To a suspension of inosine (1 Og, 37. 3mmol) and catalytic DMAP in MeCN (60mL) was added Et3N (20mL, 143mmol) and acetic anhydride (12.5mL) and the resulting solution was stirred for 1h at ambient temperature before the addition of MeOH (5mL). After stirring for 5mins, the solution was concentrated in vacuo to yield a white solid which was washed with isopropyl alcohol to afford triacetoxy inosine (12. 1g, 82percent).
Reference:
[1] Organic and Biomolecular Chemistry, 2005, vol. 3, # 3, p. 462 - 470
[2] Synthesis, 2003, # 17, p. 2639 - 2642
[3] Journal of the American Chemical Society, 1997, vol. 119, # 32, p. 7423 - 7433
[4] Journal of Organic Chemistry, 1985, vol. 50, # 15, p. 2664 - 2667
[5] Chemistry - A European Journal, 2015, vol. 21, # 33, p. 11634 - 11643
[6] Synlett, 2006, # 20, p. 3474 - 3478
[7] Journal of the Brazilian Chemical Society, 2010, vol. 21, # 5, p. 859 - 866
[8] Journal of applied chemistry of the USSR, 1984, vol. 57, # 9 pt 2, p. 1991 - 1992
[9] Patent: WO2005/54269, 2005, A1, . Location in patent: Page/Page column 14
[10] Journal of Medicinal Chemistry, 2007, vol. 50, # 4, p. 782 - 793
[11] Journal of the Chemical Society, Perkin Transactions 1: Organic and Bio-Organic Chemistry (1972-1999), 1990, # 11, p. 2937 - 2942
[12] Journal of Labelled Compounds and Radiopharmaceuticals, 2000, vol. 43, # 1, p. 11 - 28
[13] Monatshefte fur Chemie, 2003, vol. 134, # 6, p. 851 - 873
[14] Patent: EP2407474, 2012, A1, . Location in patent: Page/Page column 5
[15] Journal of Medicinal Chemistry, 2015, vol. 58, # 15, p. 6248 - 6263
13
[ 2466-76-4 ]
[ 58-63-9 ]
[ 3181-38-2 ]
Yield
Reaction Conditions
Operation in experiment
70%
With sodium hydroxide In water at 20℃; for 4 h;
General procedure: Nucleoside/nucleotide (2; 100 mM) and N-acetyl imidazole (1a;10 equiv) were dissolved in water (pH 8; adjusted with 4 MNaOH). The solution was incubated at r.t. for 4 h, and NMR spectra were periodically acquired. The product was purified byreverse-phase (C18) flash coumn chromatography (eluted at pH4 with 100 mM NH4HCO2/MeCN = 98:2 to 80:20). The fractions containing 5 were lyophilised to yield a white powder.
With dmap; triethylamine; In acetonitrile; at 20℃; for 1h;
To a suspension of inosine (1 Og, 37. 3mmol) and catalytic DMAP in MeCN (60mL) was added Et3N (20mL, 143mmol) and acetic anhydride (12.5mL) and the resulting solution was stirred for 1h at ambient temperature before the addition of MeOH (5mL). After stirring for 5mins, the solution was concentrated in vacuo to yield a white solid which was washed with isopropyl alcohol to afford triacetoxy inosine (12. 1g, 82%).
In pyridine; at 0℃; for 6h;
Acetic anhydride (16mL) was added to a suspesion of inosine (5.36g) in dry pyridine (25mL) at 0C and stirred at room temperature for 6h. The solvent was evaporated in vacuo. Water 75mL was added to the residue ,the suspension was stirred for 1/2h then filtered and washed with water (2 × 50mL) yielding the pure white product O 2', O 3', O 5' -tri-acetylinosine.
Stage #1: acetoxyisobutyryl bromide; Inosine In acetonitrile at 20℃; for 3h;
Stage #2: With acetic acid; zinc In tetrahydrofuran at 20℃; for 5h;
To a stirred suspension of inosine (2.00 g, 7.46 mmol) in dry acetonitrile (15 mL) was added dropwise 2-acetoxyisobutyryl bromide (3.89 g, 18.61 mmol, 2.5 equiv) and stirring was continued at room temperature for 3 hours. Then the mixture was poured into saturated aqueous solution of sodium bicarbonate (50 mL) and extracted with ethyl acetate (4 × 15 mL). The combined ethyl acetate extracts were washed with water (10 mL), dried over anhydrous magnesium sulfate, filtered and evaporated under vacuum to dryness; yield of 3 and 4: 2.69 g (72%). Next, the mixture of 3 and 4 (2.69 g, 5.37 mmol) was dissolved in THF (55 mL) and zinc dust (2.69 g) was added followed by acetic acid (0.25 mL). The reaction mixture was stirred at room temperature for 5 hours. After that, the mixture was filtered and the residue was washed with THF (15 mL). The combined filtrates were concentrated to about 20 mL and poured into 5% aqueous solution of EDTA trisodium salt (100 mL). The resulting solution was extracted with ethyl acetate (6 × 20 mL). The combined ethyl acetate extracts were washed 5% aqueous solution of sodium bicarbonate (20 mL) and with water (10 mL), dried over anhydrous magnesium sulfate, filtered and evaporated under vacuum to dryness; yield of 5: 1.26 g (65%).
With copper; acetic acid; zinc 1.) acetonitrile, from 5 deg C to 10 deg C, 2 h, 2.) THF, RT, 45 min; Yield given. Multistep reaction;
In acetonitrile at 5 - 10℃; for 2h; Title compound not separated from byproducts;
In nitromethane for 2.5h; Ambient temperature; Yields of byproduct given. Title compound not separated from byproducts;
In acetonitrile at 20℃; for 3h; Overall yield = 72 %; Overall yield = 2.69 g;
To a stirred suspension of inosine (2.00 g, 7.46 mmol) in dry acetonitrile (15 mL) was added dropwise 2-acetoxyisobutyryl bromide (3.89 g, 18.61 mmol, 2.5 equiv) and stirring was continued at room temperature for 3 hours. Then the mixture was poured into saturated aqueous solution of sodium bicarbonate (50 mL) and extracted with ethyl acetate (4 × 15 mL). The combined ethyl acetate extracts were washed with water (10 mL), dried over anhydrous magnesium sulfate, filtered and evaporated under vacuum to dryness; yield of 3 and 4: 2.69 g (72%).
With toluene-4-sulfonic acid; In N,N-dimethyl-formamide; for 24h;Inert atmosphere;
To a solution of Inosine (0.998 g, 3.72 mmoli) in DMF (30 ml) were added 2,2-Dimethxypropane(1.8 mL, 14.59 mmoli) and p-Toluensulfonic acid monohydrate (0.038g, 0.372 mmoli). The reaction mixture was stirred under Ar for 24 h. After the evaporation of DMF, the reaction was basified with a solution of NH3 3% and the evaporated to dryness. The residue obtained was purified by chromatography over silica gel (eluent: CH2Cl2/MeOH 95/5 v/v) to afford desiderated compound 22 as white foam (yield 80%). 1H-NMR (200MHz, DMSO-d6) d: 1.34,1.50 (6H, s, (CH3)2C), 3.6 (2H, t, CH2-5?), 4.37 (1H, m, H-4?), 4.94 (1H, m, H-3?), 5.18 (1H, t, OH 5?), 5.37 (1H, dd, J=3.7, H-2?,), 6.12 (1H, d, J=2.4, H-1?), 8.05 (1H, s, H-2), 8.32 (1H, s, H-8), 12.44 (1H, br s, NH-3). ESI MS: m/z 309.1 Da [M+H]+, C13H16N4O5 Mol. Wt. 308.29.
With p-toluenesulfonic acid monohydrate; acetic anhydride; In acetonitrile;
Example 8 Synthesis of 9-((2-acetoxyethoxy)methyl)-hypoxanthine (in the formula (I), R1 =CH2, R2 =(CH2)2, X=O, and Y=OH) from inosine. To 10 g of inosine, 12 g of 2-oxa-1,4-butanediol diacetate (2 eq.), 34 g of acetic anhydride (10 eq.), 100 ml of acetonitrile and 0.63 g (2.5 mol %) of p-toluenesulfonic acid monohydrate were added, and the mixture was refluxed with stirring at an elevated temperature for 48 hours for reaction. Then, the solvent was removed by distillation under reduced pressure from the reaction mixture, and the residue was subjected to hydrolysis with aq. NaOH. After neutralization, purification using the synthetic adsorption resin "SP-207" was carried out, whereby 3.7 g of the desired product was obtained. Yield, 47%. 1 H NMR (300 MHz, DMSO-d6) analytical values: delta, 3.44 (4H, s, H-2' & 3'), 4.30 (1H, brs, OH), 5.27 (2H, s, H-1'), 8.05 (1H, s, H-2), 8.31 (2H, s, H-8). Mass spectrum analytical value: MH+ =211.
With purine nucleoside phosphorylase from Aeromonas hydrophyla, covalently immobilized on aminopropylsilica particles In aq. phosphate buffer; dimethyl sulfoxide at 37℃; for 0.333333h; Flow reactor; Enzymatic reaction;
With sodium hydroxide; In water; at 20℃; for 4h;pH 8.0;
General procedure: Nucleoside/nucleotide (2; 100 mM) and N-acetyl imidazole (1a;10 equiv) were dissolved in water (pH 8; adjusted with 4 MNaOH). The solution was incubated at r.t. for 4 h, and NMR spectra were periodically acquired. The product was purified byreverse-phase (C18) flash coumn chromatography (eluted at pH4 with 100 mM NH4HCO2/MeCN = 98:2 to 80:20). The fractions containing 5 were lyophilised to yield a white powder.
α-D-ribofuranose-1-O-phosphate disodium salt[ No CAS ]
Yield
Reaction Conditions
Operation in experiment
> 95 %Spectr.
With purine nucleoside phosphorylase; catalase; xanthine oxidase In aq. phosphate buffer at 37℃; for 48h; Enzymatic reaction;
4.5. Scale-up reaction to isolate a-D-ribofuranosyl 1-phosphatesodium salt (aR1P) from inosine phosphorolysis
Inosine (67.0 mg, 250 mmol), PNPase (8 units), XO (0.4 units),catalase (2000 units) and a few drops of CHCl3 (to inhibit bacterialgrowth) were added to sodium phosphate buffer (50 mM, 500 mL)at pH 7.4, and the reaction mixture was incubated at 37 °C. Aftertwo days, the reaction mixturewas concentrated to ~10mL at 30 °C in vacuo and most of the sodium phosphate was removed by crystallization at 4 °C. The sample (~3 mL) was loaded on a Bio-GelP-2 column (2.5 cm * 100 cm) and eluted at ~0.8 mL/min with DI water, and fractions (~15 mL) were analyzed by 1H NMR. Fractions containing αR1P (fractions 13e21) were combined and reloaded on a second Bio-Gel P-2 column of similar dimensions, and elution gave a pure sample of αR1P for further characterization. An overall isolated yield of ~74% was determined by 1H NMR. See Tables 1 and 2 for 1H NMR (600 MHz) and 13C NMR (150 MHz) data. HRMS: [M -H]- calcd for C5H10O8P 229.0119, found 229.0122.
With aluminum (III) chloride; In methanol; at 60℃; for 2h;
Into a 1000 ml reaction flask, 100 g of inosine and 500 ml of methanol were added, and 202 g of acetanilide and 10 g of aluminum trichloride were added under stirring. The reaction was heated to 60 C. for 2 hours, and the organic solvent was distilled off under reduced pressure to obtain tetraacetyl ribose 112.8 g. The rate was 95% and the HPLC purity was 99.76%.
Stage #1: Inosine With 2-acetoxy-2-methylpropanoyl chloride; sodium iodide In acetonitrile for 1.5h; Inert atmosphere;
Stage #2: With 10 wt% Pd(OH)2 on carbon; hydrogen; sodium acetate In methanol; water
Stage #3: With ammonia In methanol
3′-Deoxyinosine (41) [60]
NaI (1.1 g, 7.5 mmol, 10 eq.) wasdissolved in anhydrous MeCN (7.5 mL) and stirred for 5 min underargon. Next, α-acetoxyisobutyrylchloride (0.38 mL, 2.6 mmol, 3.5eq.) was added, giving a white precipitate. The mixture was stirredvigorously for another 5-10 min, after which inosine (0.20 g,0.75 mmol, 1 eq.) was added in one portion. The resulting mixturewas stirred for 1.5 h after which TLC showed full conversion of SM.The mixturewas poured in aq. sat. NaHCO3/aq. sat. Na2S2O3 (30 mL)solution. Next, CHCl3 (30 mL) was added, and the layers separated.The water layer was extracted with CHCl3 (30 mL) twice more.Organic layers were combined, dried over Na2SO4, filtered andevaporated. The resulting oilwas dissolved in MeOH (3 mL) and 1Maq. NaOAc solution (1 mL) was added. Next, the flask was purgedwith N2, after which a cat. amount of Pd(OH)2/C was added. Next,the N2-atmosphere was exchanged for H2 (balloon; no bubbling)and the mixture stirred overnight. Next, the mixture was purgedwith N2 to remove residual H2-gas and filtered over a pad of Celite. The mixture was evaporated till dryness and partitioned betweenEtOAc (25 mL) and aq. sat. NaHCO3/aq. sat. Na2S2O3 solution(1:1, 20 mL). Layers were separated, and the water layer extractedtwice more with EOAc (25 mL). Organic layers were combined,dried over Na2SO4, filtered and evaporated. The resulting oil wasdissolved in 7 N NH3 in MeOH and stirred overnight. The solventwas removed, and the residue purified by column chromatography(2 → 20% MeOH/DCM) to afford 41 as a white solid (0.062 g,0.25 mmol) in 33% yield. 1H NMR (300 MHz, DMSO-d6) δ ppm 1.90(1H, ddd, J =13.2, 6.2, 2.1 Hz, H-3'), 2.21 (1H, ddd, J =13.2, 9.4,5.6 Hz, H-3"), 3.53 (1H, m, H-5'), 3.69 (1H, m, H-5"), 4.15-4.43 (1H,m, H-4'), 4.50 (1H, br. s., H-2'), 5.03 (1H, br. s., OH-50), 5.69 (1H, b'r. s.,OH-3'), 5.86 (1H, d, J =2.1 Hz, H-1'), 8.06 (1H, s, H-2), 8.33 (1H, s, H-8), 12.04 (1H, br. s, NH). Spectral data are in accordance withliterature values [60].
With Clostridium perfringens uridine phosphorylase; Aeromonas hydrophila purine nucleosidephosphorylase co-immobilized on glyoxyl-agarose In aq. phosphate buffer at 28℃; Flow reactor; Green chemistry; Enzymatic reaction;
3.9. General Procedure for the Flow Transglycosylation Reaction
General procedure: A solution of the sugar donor and the sugar acceptor was prepared in 50mMphosphate buer pH7.5. In the case of hypoxanthine (6), in order to dissolve it, the suspension was sonicated (3 10 min).The temperature was set at 28 C. The column packed with immobilized CpUP and AhPNP (0.68 g,0.68 mL) was washed with 50 mM phosphate buer pH 7.5 at 0.2 mL min1 for 10 min at atmosphericpressure. The substrate solution (2.0 mL) was flowed through the bioreactor. Residence times andconcentrations were varied as reported in Table 1. The reaction outcome was monitored by HPLC. Asample of the exiting flow stream (200 L) was diluted with a mixture of H2O/MeOH (9:1), in order toobtain a sample concentration of 0.1 mM, and was used for the analysis.