4291-63-8

Basic information

• Product Name: Cladribine
• Synonyms: CDA;CLADRIBINE;CLADRIBINE CDA;LABOTEST-BB LT01147851;2-CHLORO-2'-DEOXYADENOSINE;2CDA;2-CL-DADO;2-chloro-2’-deoxy-adenosin
• CAS NO: 4291-63-8
• Molecular Formula: C₁₀H₁₂ClN₅O₃
• Molecular Weight: 285.69
• EINECS: 224-427-9
• Product Categories: Bases & Related Reagents;Nucleotides;Pharmaceuticals;API;Anti-cancer&immunity;Inhibitors
• Mol File: 4291-63-8.mol
• Article Data: 35

Chemical Properties

• Melting Point: 181-185 °C(lit.)
• Boiling Point: 387.1 °C at 760 mmHg
• Flash Point: 187.9 °C
• Appearance: /
• Density: 1.402 g/cm³
• Storage Temp.: 2-8°C
• Solubility: Slightly soluble in water, soluble in dimethyl sulfoxide, slightly soluble in methanol, practically insoluble in acetonitrile. It shows polymorphism (5.9).
• PKA: 13.75±0.60(Predicted)
• Stability: Store in Freezer
• Merck: 14,2337
• CAS DataBase Reference: Cladribine(CAS DataBase Reference)
• NIST Chemistry Reference: Cladribine(4291-63-8)
• EPA Substance Registry System: Cladribine(4291-63-8)

Safety Data

• Hazard Codes: T
• Statements: 36/37/38-23/24/25
• Safety Statements: 26-37/39-45-36-22
• RIDADR: UN 2811 6.1 / PGIII
• WGK Germany: 3
• RTECS: AU7357560
• Hazardous Substances Data: 4291-63-8(Hazardous Substances Data)

Usage

Description

Different sources of media describe the Description of 4291-63-8 differently. You can refer to the following data:
1. Cladribine (2-chloro-2′-deoxyadenosine) is an adenosine deaminase-resistant analogue of deoxyadenosine. The drug has a broad range of in vitro activity against both lymphoid and myeloid neoplasms [mean IC50values (drug concentration required to inhibit cell growth by 50% of control): 20 to 87 nmol/L]. But it possesses little activity against multiple myeloma specimens and many solid tumor cell lines. Monocytes are highly sensitive to cladribine in vitro. Cladribine demonstrates activity against both dividing and nondividing cells and this activity distinguishes it from many other agents. It has activity in murine models of leukaemia. Cladribine is used to treat chronic progressive multiple sclerosis, hairy cell leukemia, systemic mastocytosis, and histiocytosis (including Erdheim–Chester disease and Langerhans cell histiocytosis). After a 2-hour intravenous infusion of cladribine 0.14 mg/kg/day, the mean maximum plasma drug concentration was 198 nmol/L. Intracellular concentrations of phosphorylated cladribine derivatives exceed plasma concentrations 128- to 375-fold. Cladribine penetrates into the CSF. The terminal elimination half-life (6.7 hours) is long, which suggests that the drug may be administered intermittently without loss of efficacy. The volume of distribution of cladribine is 9.2 L/kg.
2. Cladribine, an adenosine deaminase inhibitor, was introduced in the United States as a single intravenous treatment for hairy cell leukemia. The incorporation of a chlorine atom at the 2-position of deoxyadenosine renders cladribine more resistant to enzymatic attack by adenosine deaminase, resulting in a more prolonged cytotoxic effect. Cladribine efficiently crosses lymphocyte and monocyte cell membranes and is metabolized in cells to the biologically active triphosphate, which inhibits DNA synthesis. While most antineoplastic drugs are active primarily against dividing cells, cladribine destroys both resting and proliferating cells. Its potential uses in the treatment of autoimmune hemolytic anemia, multiple sclerosis, chronic lymphocytic leukemia and various lymphomas have also been evaluated.

References

[1] J.C Sipe,? J. S Romine, R. McMillan, E. Beutler, J. C. Sipe, J. S. Romine, J. Zyroff (1994) Cladribine in treatment of chronic progressive multiple sclerosis, 344, 9-13 [2] Alan Saven, Carol Burian (1999) Cladribine Activity in Adult Langerhans-Cell Histiocytosis, 93, 4125-4130 [3] https://en.wikipedia.org/wiki/Cladribine [4] Harriet M. Bryson, Eugene M. Sorkin (1993) Cladribine: A Review of its pharmacodynamic and pharmacokinetic properties and therapeutic potential in haematological malignancies, 46, 872-894

Chemical Properties

White Crystalline Solid

Originator

Johnson & Johnson (U.S.A.)

Uses

Different sources of media describe the Uses of 4291-63-8 differently. You can refer to the following data:
1. 2-Chloro-2′-deoxyadenosine (2-CdA) is a chlorinated purine nucleoside with activity against lymphoproliferative disorders, such as hairy cell leukemia (HCL) and multiple myeloma (MM). 2-CdA resists ADA degradation and is phosphorylated to CdATP in lymphocytes. CdATP incorporation into DNA induces strand breaks and the activation of apoptosis. 2-CdA may also be used in studies involving the inhibition of DNA polymerase(s).Cladribiane, like fludarabine, is a prodrug that is must be phosphorylated intracellularly to the monophosphate by the nuclear/cytosol enzyme deoxycytidine kinase (dCK) and possibly by the mitochondrial enzyme deoxyguanosine kinase (dGK).
2. It is a substituted purine nucleoside with antileukemic activity

Indications

Cladribine (Leustatin) is a synthetic purine nucleoside that is converted to an active cytotoxic metabolite by the enzyme deoxycytidine kinase. Like the other purine antimetabolites, it is relatively selective for both normal and malignant lymphoid cells and kills resting as well as dividing cells by mechanisms that are not completely understood. The drug is highly active against hairy cell leukemia, producing complete remissions in more than 60% of patients treated with a single 7-day course. Activity has also been noted in other low-grade lymphoid malignancies. The major side effect is myelosuppression.

Definition

ChEBI: 2'-Deoxyadenosine in which the hydrogen at position 2 on the purine ring has been substituted by chlorine. It inhibits the synthesis and repair of DNA, particularly in lymphocytes and monocytes, and is used as an antimetabolite antineoplastic drug for the treatment of lymphoid malignancies including hairy-cell leukaemia and chronic lymphocytic leukaemia.

Manufacturing Process

Manufacturing process for Cladribine includes these steps as follows: Preparation of 2',3',5'-O-triacetyl guanosine;Preparation of 9-(2',3',5'-O-triacetyl-β-D-ribofuranosyl)-2-amino-6- chloropurine;Preparation of 9-(2',3',5'-O-triacetyl-β-D-ribofuranosyl)-2,6-dichloropurine;Preparation of 2-chloroadenosine;Preparation of 2-chloro-(3',5'-O-tetraisopropyldisiloxyl)adenosine; Preparation of 2-chloro-2'-O-phenoxythiocarbonyl-(3',5'-O-tetraisopropyldisiloxyl)adenosine; Preparation of 2-chloro-2'-deoxy-(3',5'-O-tetraisopropyldisiloxyl)adenosine; Preparation of 2-chloro-2'-deoxy-adenosine.

Brand name

Leustatin (Ortho Biotech).

General Description

The drug is available in a 10-mg or 10-mL single-use vialfor IV use. Cladribine is used for chronic lymphocyticleukemia, hairy cell leukemia, and non-Hodgkin’s lymphoma.The mechanism of action of this purine deoxyadenosineanalog involves incorporation into DNA resultingin inhibition of DNA chain extension and inhibitionof DNA synthesis and function. This incorporation intoDNA occurs via the triphosphate metabolite active species.The 2-chloro group on the adenine ring produces resistanceto breakdown by adenosine deaminase. Resistance to the anticancereffects can occur because of decreased expressionof the activating enzyme or overexpression of the catabolicenzymes. Oral bioavailability is variable and averages about50%. The drug crosses the blood-brain barrier; however,CSF concentrations reach only 25% of those in plasma. Thedrug is selectively activated inside the cell, and intracellularconcentrations of phosphorylated metabolites exceed thosein plasma. Toxicities include myelosuppression, neutropenia,immunosuppression, fever, nausea, and vomiting.

Biochem/physiol Actions

Deoxyadenosine analog resistant to adenosine deaminase; antileukemic with immunosuppressive activity

Clinical Use

Antineoplastic agent: Hairy cell leukaemia (HCL) Chronic lymphocytic leukaemia (CLL) in patients who have failed to respond to standard regimens.

Drug interactions

Potentially hazardous interactions with other drugs Antipsychotics: avoid with clozapine - increased risk of agranulocytosis. Antivirals: avoid with lamivudine. Caution when administering with any other immunosuppressive or myelosuppressive therapy

Metabolism

Cladribine is extensively distributed and penetrates into the CNS. Cladribine is phosphorylated within cells by deoxycytidine kinase to form 2-chlorodeoxyadenosine- 5′-monophosphate which is further phosphorylated to the diphosphate by nucleoside monophosphate kinase and to the active metabolite 2-chlorodeoxyadenosine-5′- triphosphate (CdATP) by nucleoside diphosphate kinase. CdATP inhibits DNA synthesis and repair, particularly in lymphocytes and monocytesThere is little information available on the route of excretion of cladribine in man. An average of 18% of the administered dose has been reported to be excreted in urine of patients with solid tumours during a 5-day continuous intravenous infusion.

InChI:InChI=1/C10H12ClN5O3/c11-10-14-8(12)7-9(15-10)16(3-13-7)6-1-4(18)5(2-17)19-6/h3-6,17-18H,1-2H2,(H2,12,14,15)/t4-,5-,6-/m1/s1

Synthetic route

3-benzyl-1-{2-chloro-9-[2-deoxy-3,5-di-O-(p-toluoyl)-β-D-erythro-pentofuranosyl]-purin-6-yl}-2-propylimidazolium iodide → 2-chloro-2'-deoxyadenosine (4291-63-8)

Conditions	Yield
With ammonia In methanol at 60℃; for 11h;	100%
With ammonia In methanol at 60℃;	59%

2-chloro-N6,N6-dibenzoyl-3′,5′-O-dibenzoyl-2′-deoxyadenosine (1448245-68-8) → 2-chloro-2'-deoxyadenosine (4291-63-8)

Conditions	Yield
With ammonia In methanol at 0 - 20℃; for 12h;	95%

9-(3,5-di-O-benzoyl-2-deoxy-β-D-erythro-pentofuranosyl)-2,6-dichloropurine (500225-62-7) → 2-chloro-2'-deoxyadenosine (4291-63-8)

Conditions	Yield
With ammonia In methanol; dichloromethane at 80℃; for 7h;	94%

6-amino-2-chloro-9-(2'deoxy-3',5'-di-O-acetyl-β-D-erythro-pentofuranosyl)-9H-purine (146196-13-6) → 2-chloro-2'-deoxyadenosine (4291-63-8)

Conditions	Yield
With sodium carbonate In methanol at 20℃; for 2h; pH=8 - 9;	93%
With ammonia In methanol at 0 - 20℃;	0.62 g

2-chloro-6-amino-9-[3,5-di-O-(4-chlorobenzoyl)-2-deoxy-β-D-ribofuranosyl]-purine (908006-51-9) + 2-chloro-6-trimethylsilylamino-9-[3,5-di-O-(4-chlorobenzoyl)-2-deoxy-β-D-ribofuranosyl]-purine (1266098-30-9) → 2-chloro-2'-deoxyadenosine (4291-63-8)

Conditions	Yield
With sodium methylate In methanol at 20 - 30℃; for 6h;	90%

2'-deoxyribose 1-phosphate diammonium salt + 2-chloroadenine (1839-18-5) → 2-chloro-2'-deoxyadenosine (4291-63-8)

Conditions	Yield
With magnesium hydroxide; purine nucleoside phosphorylase In water at 45℃;	88%

9-(3,5-di-O-acetyl-2-deoxy-β-D-erythro-pentofuranosyl)-2,6-dichloropurine (24638-92-4) → 2-chloro-2'-deoxyadenosine (4291-63-8)

Conditions	Yield
With ammonia In methanol; dichloromethane at 80℃; for 7h;	87%

2,6-Dichloro-9-(2-deoxy-3,5-di-O-p-toluoyl-β-D-erythro-pentofuranosyl)-purine (38925-80-3) → 2-chloro-2'-deoxyadenosine (4291-63-8)

Conditions	Yield
With ammonia In methanol at 110℃; for 5h; Sealed tube;	86%
With ammonia In methanol at 100℃; for 5h;	71%

2-chloro-9-[2-deoxy-3,5-di-O-(p-toluoyl)-β-D-erythro-pentofuranosyl]-6-(2-pentylimidazol-1-yl)purine (914084-44-9) → 2-chloro-2'-deoxyadenosine (4291-63-8)

Conditions	Yield
With ammonia In methanol at 60℃; for 13h;	85%

2-chloro-9-[2-deoxy-3,5-di-O-(p-toluoyl)-β-D-erythro-pentofuranosyl]-6-(2-propylimidazol-1-yl)purine (914084-41-6) + methanol (67-56-1) → 2-chloro-9-(2'deoxy-β-D-erythro-pentofuranosyl)-6-methoxy-9H-purine (146196-07-8) + 2-chloro-2'-deoxyadenosine (4291-63-8)

Conditions	Yield
With ammonia at 40℃; for 15h;	A 85% B n/a

9-(3,5-di-O-benzoyl-2-deoxy-β-D-erythro-pentofuranosyl)-2-chloro-6-O-(2,4,6-triisopropylbenzenesulfonyl)purine (500225-59-2) → 2-chloro-2'-deoxyadenosine (4291-63-8)

Conditions	Yield
With ammonia In methanol; dichloromethane at 80℃; for 7h;	83%

2,6-dichloro-9-(2-deoxy-3,5-di-p-toluoyl-O-β-D-ribofuranosyl)purine → 2-chloro-2'-deoxyadenosine (4291-63-8)

Conditions	Yield
With ammonia In methanol at 50℃; for 10h;	82%

2'-Deoxyguanosine (961-07-9) + 2-chloroadenine (1839-18-5) → 2-chloro-2'-deoxyadenosine (4291-63-8)

Conditions	Yield
With 1A cells; E. coli BMT 4D In phosphate buffer at 65℃; for 4h; pH=7.5;	81%
With purine nucleoside 2’-deoxyribosyltransferase from Trypanosoma brucei immobilized on glutaraldehyde-activated MagReSynAmine microspheres In aq. phosphate buffer at 50℃; for 0.333333h; pH=6; Enzymatic reaction;

2,6-dichloro 2’-deoxyriboside (37390-66-2) → 2-chloro-2'-deoxyadenosine (4291-63-8)

Conditions	Yield
With ammonium hydroxide In acetonitrile at 20℃; for 24h;	79%

2,6-di-chloro-9-(3',5'-di-O-p-methoxybenzoyl-2'-deoxy-D-ribofuranosyl)purine (1384553-30-3) → 2-chloro-2'-deoxyadenosine (4291-63-8)

Conditions	Yield
With methanol; ammonia In dichloromethane at 80℃;	79%

2-chloro-6-heptanoylamido-9-(2-deoxy-3,5-di-O-p-toluoyl-β-D-erythero pentofuranosyl)purine → 2-chloro-2'-deoxyadenosine (4291-63-8)

Conditions	Yield
With sodium methylate In methanol at 10 - 50℃; for 1.33333h; Heating / reflux;	72%
With sodium methylate In methanol at 20 - 50℃; for 0.333333h;	72%

2-chloro-3′,5′-di-O-(t-butyldimethylsilyl)-2′-deoxyadenosine → 2-chloro-2'-deoxyadenosine (4291-63-8)

Conditions	Yield
With potassium fluoride In methanol at 80℃; for 24h;	72%

α-D-2′-deoxyribofuranose-1-O-phosphate bis(cyclohexylammonium) salt (98693-55-1, 102783-28-8) + 2-chloroadenine (1839-18-5) → 2-chloro-2'-deoxyadenosine (4291-63-8)

Conditions	Yield
With purine nucleoside phosphorylase; calcium hydroxide at 45℃; for 48h; pH=9.3; Enzymatic reaction;	72%

2-chloro-9-[2-deoxy-3,5-di-O-(p-toluoyl)-β-D-erythro-pentofuranosyl]-6-(2-pentylimidazol-1-yl)purine (914084-44-9) → 6-amino-2-chloro-9-(2-deoxy-α-D-erythro-pentofuranosyl)purine (5542-92-7) + 2-chloro-2'-deoxyadenosine (4291-63-8)

Conditions	Yield
With ammonia In methanol at 80℃; for 13h;	A n/a B 70%

2-chloroadenine (1839-18-5) + 7-methyl-2′-deoxyguanosine hydroiodide → 2-chloro-2'-deoxyadenosine (4291-63-8)

Conditions	Yield
With potassium dihydrogenphosphate; Escherichia coli purine nucleoside phosphorylase In aq. buffer at 20℃; for 144h; pH=7.5; Enzymatic reaction;	70%

2-chloroadenine (1839-18-5) + thymidine (50-89-5) → 2-chloro-2'-deoxyadenosine (4291-63-8)

Conditions	Yield
Stage #1: thymidine With magnesium(II) chloride hexahydrate; E. coli thymidine phosphorylase In aq. phosphate buffer at 40℃; for 120h; pH=7.20; QAE Sephadex-nPi; Stage #2: 2-chloroadenine With recombinant E. coli purine nucleoside phosphorylase In aq. phosphate buffer at 40℃; for 96h; pH=8.0; QAE Sephadex-nPi;	59%
With immobilized recombinant Geobacillus stearothermophilus BKM-2194 purine nucleoside phosphorylase II/pyrimidine nucleoside phosphorylase In dimethyl sulfoxide at 75℃; for 4h; pH=7.5; aq. phosphate buffer; Enzymatic reaction;	86 %Chromat.
With potassium phosphate; Geobacillus thermoglucosidasius purine nucleoside phosphorylase; Thermus thermophilus pyrimidine nucleoside phosphorylase In water at 70℃; for 1h; pH=7; Enzymatic reaction;

9-(3,5-di-O-benzoyl-2-deoxy-β-D-erythro-pentofuranosyl)-2-chloro-6-O-(6-methylbenzenesulfonyl)purine (500225-60-5) → 2-chloro-2'-deoxyadenosine (4291-63-8)

Conditions	Yield
With ammonia In methanol; dichloromethane at 80℃; for 7h;	43%

2'-deoxyuridine (951-78-0) + 2-chloro-N6-dimethylaminomethyleneadenine → 2-chloro-2'-deoxyadenosine (4291-63-8)

Conditions	Yield
With ammonium hydroxide 1.) EtOH, DMSO, alginate gel-entrapped cells of auxotropHic thymine-dependent strain of E. coli, acetate buffer pH 5.8, 37 deg C, 16 h, 2.) room temperature, overnight; Yield given. Multistep reaction;

2-deoxy-3,5-di-O-p-toluoyl-α-D-erythro-pentofuranosyl chloride (4330-21-6) + 2,6-dichloro-7H-purine (5451-40-1) → 2-chloro-2'-deoxyadenosine (4291-63-8) + 6-amino-2-chloro-7-(2-deoxy-β-D-erythro-pentofuranoyl)-7H-purine

Conditions	Yield
With ammonia; sodium hydride Yield given. Multistep reaction. Yields of byproduct given;
Stage #1: 2,6-dichloro-7H-purine With sodium hydride In acetonitrile at 20℃; for 1.5h; Inert atmosphere; Stage #2: 2-deoxy-3,5-di-O-p-toluoyl-α-D-erythro-pentofuranosyl chloride In acetonitrile for 24.5h; Inert atmosphere; Stage #3: With ammonia In methanol at 100℃; for 6h;	A 0.4 g B 0.1 g

9-(3,5-di-O-acetyl-2-deoxy-β-D-erythro-pentofuranosyl)-2-chloro-6-O-(2,4,6-triisopropylbenzenesulfonyl)purine (500225-58-1) → 2-chloro-2'-deoxyadenosine (4291-63-8)

Conditions	Yield
With ammonia In methanol; dichloromethane at 80℃; for 7h;

2-Chloro-9-((2R,3aS,9aR)-5,5,7,7-tetraisopropyl-tetrahydro-1,4,6,8-tetraoxa-5,7-disila-cyclopentacycloocten-2-yl)-9H-purin-6-ylamine (136850-20-9) → 2-chloro-2'-deoxyadenosine (4291-63-8)

Conditions	Yield
With ammonium fluoride In methanol Heating;

2'-deoxyribose 1-phosphate diammonium salt → 2-chloro-2'-deoxyadenosine (4291-63-8)

Conditions	Yield
Multi-step reaction with 2 steps 1: 91 percent / purine nucleoside phosphorylase / H2O / 45 °C 2: 79 percent / aq. NH3 / acetonitrile / 24 h / 20 °C View Scheme

2,6 dichloropurine (5451-40-1) → 2-chloro-2'-deoxyadenosine (4291-63-8)

Conditions	Yield
Multi-step reaction with 2 steps 1: 95 percent / NH3 / methanol / 24 h / 160 °C 2: 88 percent / purine nucleoside phosphorylase; Mg(OH)2 / H2O / 45 °C View Scheme
Multi-step reaction with 6 steps 1: SnCl4 / acetonitrile / 20 °C 2: NH3 / methanol / 20 °C 3: pyridine / 20 °C 4: DMAP / acetonitrile / 20 °C 5: (Me3Si)3SiH; AIBN / dioxane / Heating 6: NH4F / methanol / Heating View Scheme
Multi-step reaction with 3 steps 1: 67 percent / NH3, MeOH / 12 h / 100 °C 2: 75 percent / dimethylformamide / Ambient temperature 3: 2.) aq. NH3 / 1.) EtOH, DMSO, alginate gel-entrapped cells of auxotropHic thymine-dependent strain of E. coli, acetate buffer pH 5.8, 37 deg C, 16 h, 2.) room temperature, overnight View Scheme
Multi-step reaction with 2 steps 1: 59 percent / 1.) NaH / acetonitrile / 1.) r.t., 30 min; 2.) 15 h 2: 71 percent / ammonia / methanol / 5 h / 100 °C View Scheme

bis(cyclohexylamine) 3',5'-O-bis(4-chlorobenzoyl)-2-deoxy-α-D-ribosyl-1-phosphate → 2-chloro-2'-deoxyadenosine (4291-63-8)

Conditions	Yield
Multi-step reaction with 3 steps 1: 92 percent / NH3 / methanol / 24 h / 20 °C 2: 91 percent / purine nucleoside phosphorylase / H2O / 45 °C 3: 79 percent / aq. NH3 / acetonitrile / 24 h / 20 °C View Scheme
Multi-step reaction with 2 steps 1: 92 percent / NH3 / methanol / 24 h / 20 °C 2: 88 percent / purine nucleoside phosphorylase; Mg(OH)2 / H2O / 45 °C View Scheme

acetic anhydride (108-24-7) + 2-chloro-2'-deoxyadenosine (4291-63-8) → 6-amino-2-chloro-9-(2'deoxy-3',5'-di-O-acetyl-β-D-erythro-pentofuranosyl)-9H-purine (146196-13-6)

Conditions	Yield
With pyridine for 3h;	92%
With pyridine for 2h; Ambient temperature;	81%

2-chloro-2'-deoxyadenosine (4291-63-8) → 2-azido-9-(2-deoxy-β-D-erythro-pentofuranosyl)adenine (404839-80-1)

Conditions	Yield
Stage #1: 2-chloro-2'-deoxyadenosine With hydrazine hydrate at 20℃; for 16h; Stage #2: With acetic acid; sodium nitrite In water for 1h; cooling;	91%
Multi-step reaction with 2 steps 1: H2NNH2*H2O / 20 °C 2: NaNO2; acetic acid / H2O / 0 °C View Scheme

ethylamine (75-04-7) + 2-chloro-2'-deoxyadenosine (4291-63-8) → 2-ethylamino-2’-deoxyadenosine

Conditions	Yield
In methanol at 130℃; for 24h;	90%

2-chloro-2'-deoxyadenosine (4291-63-8) + tert-butylchlorodiphenylsilane (58479-61-1) → 2-chloro-9-<2-deoxy-5-O-<(1,1-dimethylethyl)diphenylsilyl>-β-D-erythro-pentofuranosyl>-9H-purin-6-amine (156834-09-2)

Conditions	Yield
With pyridine for 14h;	83%

1,3-Dichloro-1,1,3,3-tetraisopropyldisiloxane (69304-37-6) + 2-chloro-2'-deoxyadenosine (4291-63-8) → 2-Chloro-9-((2R,3aS,9aR)-5,5,7,7-tetraisopropyl-tetrahydro-1,4,6,8-tetraoxa-5,7-disila-cyclopentacycloocten-2-yl)-9H-purin-6-ylamine (136850-20-9)

Conditions	Yield
With pyridine at 5 - 20℃; for 1.5h;	83%

2-chloro-2'-deoxyadenosine (4291-63-8) + N,N-dimethylformamide diethyl diacetal (1188-33-6) → 2-chloro-9-(2'-deoxy-β-D-erythro-pentofuranosyl)-6-<<(dimethylamino)methylidene>amino>-9H-purine (146196-18-1)

Conditions	Yield
In N,N-dimethyl-formamide Ambient temperature;	82%

allyl alcohol (107-18-6) + 2-chloro-2'-deoxyadenosine (4291-63-8) → 2-allyloxy-6-amino-9-[2-deoxy-β-D-erythro-pentofuranosyl]-9H-purine (916755-74-3)

Conditions	Yield
With sodium allyloxide at 60℃; for 2h;	79%
Stage #1: allyl alcohol With sodium In paraffin oil at 0℃; for 1h; Inert atmosphere; Stage #2: 2-chloro-2'-deoxyadenosine In paraffin oil at 88℃; for 12h;	62%

tert-butyldimethylsilyl chloride (18162-48-6) + 2-chloro-2'-deoxyadenosine (4291-63-8) → 5'-O-tert-butyldimethylsilylcladribine (128126-38-5)

Conditions	Yield
With 1H-imidazole In N,N-dimethyl-formamide at 20℃; for 20h; Inert atmosphere;	75%
With 1H-imidazole In pyridine at 20℃;

2-chloro-2'-deoxyadenosine (4291-63-8) + 1-amino-2-propene (107-11-9) → 2-allylamino-2’-deoxyadenosine

Conditions	Yield
In methanol at 130℃; for 24h;	75%

p-toluenesulfonyl chloride (98-59-9) + 2-chloro-2'-deoxyadenosine (4291-63-8) → C17H18ClN5O5S

Conditions	Yield
With pyridine; triethylamine at 0 - 20℃; for 24h;	74%

2-chloro-2'-deoxyadenosine (4291-63-8) + benzyl alcohol (100-51-6) → 6-amino-2-benzyloxy-9-(2'-deoxy-β-D-erythro-pentofuranosyl)purine

Conditions	Yield
Stage #1: benzyl alcohol With sodium In paraffin oil at 80℃; for 0.75h; Inert atmosphere; Stage #2: 2-chloro-2'-deoxyadenosine With silicon In acetonitrile; paraffin oil at 85℃; for 12h;	71%

Upstream product

• 38925-80-3 2,6-Dichloro-9-(2-deoxy-3,5-di-O-p-toluoyl-β-D-erythro-pentofuranosyl)-purine 
• 69992-10-5 3',5'-di-O-acetyl-2'-deoxyguanosine 
• 1839-18-5 2-chloroadenine 
• 500225-56-9 2-amino-9-(3,5-di-O-benzoyl-2-deoxy-β-D-erythro-pentofuranosyl)-6-O-(2,4,6-triisopropylbenzenesulfonyl)purine 
• 500225-57-0 2-amino-9-(3,5-di-O-benzoyl-2-deoxy-β-D-erythro-pentofuranosyl)-6-O-(4-methylbenzenesulfonyl)purine 
• 500225-61-6 2-amino-9-(3,5-di-O-benzoyl-2-deoxy-β-D-erythro-pentofuranosyl)-6-chloropurine 
• 69992-11-6 2-amino-6-chloro-9-[(3’,5’-di-O-acetyl-2’-deoxy)-β-D-ribofuranosyl]purine 
• 119771-85-6 9-(3,5-di-O-acetyl-2-deoxy-β-D-erythro-pentofuranosyl)-2-amino-6-O-(2,4,6-triisopropylbenzenesulfonyl)purine 
• 59921-49-2 3',5'-di-O-benzoyl-2'-deoxyguanosine 
• 149681-75-4 Thiocarbonic acid O-[(2R,3R,3aR,9aR)-2-(6-amino-2-chloro-purin-9-yl)-5,5,7,7-tetraisopropyl-tetrahydro-1,4,6,8-tetraoxa-5,7-disila-cyclopentacycloocten-3-yl] ester O-phenyl ester 
• 111556-90-2 (6aR,8R,9R,9aS)-8-(6-amino-2-chloro-9H-purin-9-yl)-2,2,4,4-tetraisopropyltetrahydro-6H-furo[3,2-f][1,3,5,2,4]trioxadisilocin-9-ol 
• 146-77-0 2-Chloroadenosine 
• 15373-23-6 (2R,3R,4R,5R)-2-((benzoyloxy)methyl)-5-(2,6-dichloro-9H-purin-9-yl)tetrahydrofuran-3,4-diyl dibenzoate 
• 6974-32-9 1-O-acetyl-2,3,5-tri-O-benzoyl-β-D-ribofuranose 

Downstream Products

• 1839-18-5 2-chloroadenine 
• 50-89-5 thymidine 
• 146331-54-6 2-chloro-9-<2'-deoxy-5'-O-(4,4'-dimethoxytrityl)-β-D-erythro-pentofuranosyl>-6-<<(dimethylamino)methylidene>amino>-9H-purine 3'-triethylammonium phosphonate 
• 146196-21-6 2-chloro-9-<2'-deoxy-5'-O-(4,4'-dimethoxytrityl)-β-D-erythro-pentofuranosyl>-6-<<(dimethylamino)methylidene>amino>-9H-purine 
• 169765-81-5 N-[9-{(2R,4S,5R)-5-[Bis-(4-methoxy-phenyl)-phenyl-methoxymethyl]-4-hydroxy-tetrahydro-furan-2-yl}-2-(3-imidazol-1-yl-propylamino)-9H-purin-6-yl]-isobutyramide 
• 156834-10-5 2-chloro-9-<2-deoxy-5-O-<(1,1-dimethylethyl)diphenylsilyl>-3-O-(phenoxythiocarbonyl)-β-D-erythro-pentofuranosyl>-9H-purin-6-amine 
• 156834-11-6 2-chloro-9-<2,3-dideoxy-5-O-<(1,1-dimethylethyl)diphenylsilyl>-β-D-glycero-pentofuranosyl>-9H-purin-6-amine 

Relevant articles and documents

Efficient synthesis of cladribine via the metal-free deoxygenation

The efficient synthesis of cladribine via the metal-free deoxygenation was developed. Using (Bu4N)2S2O8/HCO2Na instead of Bu3SnH/AIBN as deoxygenation system, cladribine could be obtained with good yield and even on tens of grams scales. The intermediates and product could be purified by simple work-up process and chromatography was avoided, which showed the good future for industrial applications.

A concise synthesis of isoguanine 2'-deoxyriboside and its adenine-like triplex formation when incorporated into DNA

A concise synthesis of 2'-deoxyisoguanosine is achieved whereby 2,6-dichloropurine is glycosylated using the Hoffer sugar to give a pair of beta-configured nucleoside N9/N7 regioisomers that are aminated using methanolic ammonia with concomitant deprotection of the sugar. Following chromatographic separation, pure 2-chloro-2'-deoxyadenosine was isolated as a single isomer. Displacement of the C2 chlorine atom using sodium benzyloxide, followed by hydrogenolysis of the benzyl group, gives 2'-deoxyisoguanosine. Isoguanine was incorporated into DNA by solid supported synthesis using the suitably protected 2-allyloxy-2'-deoxyadenosine phosphoramidite with the allyl group being removed post-oligomerisation under Noyori conditions. DNA melting studies showed isoguanine to exhibit adenine-like triplex formation.

Thermodynamic Reaction Control of Nucleoside Phosphorolysis

Nucleoside analogs represent a class of important drugs for cancer and antiviral treatments. Nucleoside phosphorylases (NPases) catalyze the phosphorolysis of nucleosides and are widely employed for the synthesis of pentose-1-phosphates and nucleoside analogs, which are difficult to access via conventional synthetic methods. However, for the vast majority of nucleosides, it has been observed that either no or incomplete conversion of the starting materials is achieved in NPase-catalyzed reactions. For some substrates, it has been shown that these reactions are reversible equilibrium reactions that adhere to the law of mass action. In this contribution, we broadly demonstrate that nucleoside phosphorolysis is a thermodynamically controlled endothermic reaction that proceeds to a reaction equilibrium dictated by the substrate-specific equilibrium constant of phosphorolysis, irrespective of the type or amount of NPase used, as shown by several examples. Furthermore, we explored the temperature-dependency of nucleoside phosphorolysis equilibrium states and provide the apparent transformed reaction enthalpy and apparent transformed reaction entropy for 24 nucleosides, confirming that these conversions are thermodynamically controlled endothermic reactions. This data allows calculation of the Gibbs free energy and, consequently, the equilibrium constant of phosphorolysis at any given reaction temperature. Overall, our investigations revealed that pyrimidine nucleosides are generally more susceptible to phosphorolysis than purine nucleosides. The data disclosed in this work allow the accurate prediction of phosphorolysis or transglycosylation yields for a range of pyrimidine and purine nucleosides and thus serve to empower further research in the field of nucleoside biocatalysis. (Figure presented.).

Enzymatic Synthesis of Therapeutic Nucleosides using a Highly Versatile Purine Nucleoside 2’-DeoxyribosylTransferase from Trypanosoma brucei

The use of enzymes for the synthesis of nucleoside analogues offers several advantages over multistep chemical methods, including chemo-, regio- and stereoselectivity as well as milder reaction conditions. Herein, the production, characterization and utilization of a purine nucleoside 2’-deoxyribosyltransferase (PDT) from Trypanosoma brucei are reported. TbPDT is a dimer which displays not only excellent activity and stability over a broad range of temperatures (50–70 °C), pH (4–7) and ionic strength (0–500 mM NaCl) but also an unusual high stability under alkaline conditions (pH 8–10). TbPDT is shown to be proficient in the biosynthesis of numerous therapeutic nucleosides, including didanosine, vidarabine, cladribine, fludarabine and nelarabine. The structure-guided replacement of Val11 with either Ala or Ser resulted in variants with 2.8-fold greater activity. TbPDT was also covalently immobilized on glutaraldehyde-activated magnetic microspheres. MTbPDT3 was selected as the best derivative (4200 IU/g, activity recovery of 22 %), and could be easily recaptured and recycled for >25 reactions with negligible loss of activity. Finally, MTbPDT3 was successfully employed in the expedient synthesis of several nucleoside analogues. Taken together, our results support the notion that TbPDT has good potential as an industrial biocatalyst for the synthesis of a wide range of therapeutic nucleosides through an efficient and environmentally friendly methodology.