142340-99-6

Basic information

• Product Name: Adefovir dipivoxil
• Synonyms: BIS POM PMEA;BIS(PIVALOYLOXYMETHYL)-9-[2-(PHOSPHONOMETHOXY)ETHYL]ADENINE;9-[2-[bis[(pivaloyloxy)methoxy]phosphinyl]methoxy]ethyl]adenine;ADEFOVIR DIPIVOXIL;ADEFOVIR PIVOXIL;Adefovir Dipivoxyl;Bis(Pivaloyloxymethyl)-9-[(R)-2-(Phosphonomethoxy)Ethyl]Adenine;AdefovirDipivoxl98.5%Min
• CAS NO: 142340-99-6
• Molecular Formula: C₂₀H₃₂N₅O₈P
• Molecular Weight: 501.470541
• EINECS: 200-001-8
• Product Categories: Active Pharmaceutical Ingredients;Adefovir;APIs;Other Products;Bases & Related Reagents;Inhibitors;Intermediates & Fine Chemicals;Nucleotides;Pharmaceuticals;Pharmaceutical raw material;API;Bis-POM PMEA, Preveon, Hepsera
• Mol File: 142340-99-6.mol
• Article Data: 20

Chemical Properties

• Melting Point: 98-102°C
• Boiling Point: 641 °C at 760 mmHg
• Flash Point: 341.5 °C
• Appearance: It has broad-spectrum antiviral activity
• Density: 1.35 g/cm³
• Vapor Pressure: 2.52E-16mmHg at 25°C
• Refractive Index: 1.569
• Storage Temp.: −20°C
• Solubility: ethanol: soluble50mg/mL
• PKA: 4.16±0.10(Predicted)
• Merck: 14,151
• CAS DataBase Reference: Adefovir dipivoxil(CAS DataBase Reference)
• NIST Chemistry Reference: Adefovir dipivoxil(142340-99-6)
• EPA Substance Registry System: Adefovir dipivoxil(142340-99-6)

Safety Data

• Hazard Codes: Xn
• Statements: 20/21/22
• Safety Statements: 36/37
• WGK Germany: 3
• RTECS: UA2459362
• Hazardous Substances Data: 142340-99-6(Hazardous Substances Data)

Usage

Regulating human immune system

Adefovir dipivoxil regulates the immune system and let the immune system to attack liver cells of the intrusion of HBV , and clear the virus, but this method will develop resistance, at the same time for patients with renal dysfunction or potential renal dysfunction risk, the use of adefovir dipivoxil chronic treatment will lead to renal toxicity. If eating 1 mg every day, in the three months will produce nephrotoxicity, this will lead to severe renal failure. These patients should be closely monitoring renal function and making appropriate dosage adjustments. Bisphosphonates is quick conversion of adefovir dipivoxil in vivo, adefovir dipivoxil is a kind of single adenosine monophosphate acyclic nucleoside analogues, became to activity of the metabolites of adefovir in cellular kinases by phosphorylation in cellular kinases. A Duff Vee two phosphate through the following two ways to suppress HBV DNA polymerase (reverse transcriptase); one is with the natural substrate of deoxyadenosine triphosphate competition, the second is the integration of viral DNA and induce DNA chain elongation terminated. A Duff Vee two phosphate to HBV DNA polymerase inhibition constant (KI) is 0.1μM, but of human DNA polymeraseα and γ is weak and Ki values were 1.18μM and 0.97 μM. Anti-viral activity: in the human hepatoma cell line transfected with HBV, the concentration of A Duff Vee inhibited 50% viral DNA replication (IC50) is from 0.2 to 2.5uM. Adefovir dipivoxil applies for the treatment of hepatitis B virus replication activity and serum amino acid transfer enzyme and persistently elevated liver decompensation adult patients with chronic hepatitis B patients. Liver injury is often encountered in the course of hepatitis B treatment, hepatitis B therapy is inappropriate, as well as long-term use of drugs on the liver damage, will lead to the occurrence of liver damage. After long-term taking adefovir dipivoxil tablets, once the withdrawal will aggravate the damage of liver function. Therefore, for stopping taking the patients should be monitored for liver function. Adefovir dipivoxil is more moderate suitable for long-term use, suitable for patients with lamivudine resistant patients, their chances of producing drug resistance is small, because the amount is less, side effects are small. Entecavir is new, antiviral effect is also strong, if not treated with lamivudine, the possible resistance is the smallest, but it and lamivudine have cross resistance, if treated with lamivudine to take entecavir produced resistance rate is much greater. The above information is lookchem Hanya edited.

Entecavir

Entecavir is a new generation of guanine nucleoside analogues oral medicine for treatment of hepatitis B virus infection in, mainly for the treatment of adult patients with viral replication activity and serum transaminase continued to increase, or liver tissue for pathological activity of chronic hepatitis B, is currently down virus the fastest and the most powerful, the mutation rate lowest nucleoside analogues. Data show that different in patients with chronic hepatitis B, including nucleoside naive and nucleoside treated and liver cirrhosis patients, using well entecavir tablets in the treatment can control the disease rapidly and easily reach the treatment of reality end, namely the hepatitis B virus unmeasured; through adherence to treatment, a considerable portion of patients can be arrived at the end of treatment satisfaction, namely e antigen serology conversion, some patients can even reach the ideal for the treatment of end, namely surface antigen negative.

Nephrotoxicity

Nephrotoxicity is the most interesting problem in the clinical application of adefovir dipivoxil. In the global phase III clinical study and follow-up study, the general definition of renal toxicity to confirm≥0.5 mg/dL, increase serum creatinine compared with the baseline, and serum phosphorus <1.5mg/dl; the three years data show that HBeAg positive patients treat 144 weeks in no cases of renal toxicity; HBeAg negative patients are 3 cases (2.4%), appeared serum creatinine increasing, but not with phosphorus decreased subsequently (2 cases of drug withdrawal, 1 case to continue the medication) indexes returned to normal. For patients with chronic hepatitis B in liver transplantation, before and after transplantation taking adefovir dipivoxil, a part increase serum creatinine, but mostly with other multiple risk factors, such as the use of immunosuppressive agents and (or) other nephrotoxic drugs, leading to potential renal damage. In the these, many patients before treatment, most of them in the dose adjustment can still safe to use, about 2% of the patients have severe renal impairment and discontinuation.196 cases of YMDD positive chronic hepatitis B patients after transplantation, proportion of renal toxicity in receiving adefovir dipivoxil in the treatment is 13%, but these patients received cyclosporine or tacrolimus treatment, of which 13 cases had existed before the treatment of complications. 8 cases had renal insufficiency, 4 patients with decompensated cirrhosis, 2 cases received other nephrotoxic drugs treatment. Therefore, based in compensated chronic hepatitis B patients up to 3 years of research results, and in patients with liver transplantation results show that adefovir dipivoxil 10mg/d safety and placebo groups are similar, have no clinically significant renal events. There are patients with renal damage caused by drug taking at the same time, should close monitoring indexes of renal function during the medication use and before, and used with caution; according to creatinine clearance rate (ml/min) to adjust the dosing interval of patients with impaired renal function.

Lamivudine

Lamivudine is a new antiviral drug, belonging to nucleoside reverse transcriptase inhibitors, having a strong inhibitory effect in vitro and animal experimental infection of hepatitis B virus (HBV), can inhibit the synthesis of HIV virus; the drug produced by the GlaxoSmithKline Co. In the early 90s, they are used for the treatment of AIDS drugs in Europe and North American countries. In the middle of the 1990 medical experts found that they have inhibition to hepatitis B virus DNA, in 1998 the United States Food and Drug Administration (FDA) approved the first drug for treatment of hepatitis B treatment. In China, the State Food and Drug Administration approved the drug import mainly used as medicine in the treatment of hepatitis B, Chinese product name as "He Puding". In 1999, officially began on the mainland. Chinese sold after 10 years of clinical verification, lamivudine is the only proven to delay Hepatitis cirrhosis progress, fewer side effects, less cost of medication, currently has 2 million of the country's hepatitis B patients are using. Lamivudine can be metabolized to lamivudine three phosphate in HBV infection cells and normal cells, it is the active form of lamivudine, both inhibitors of HBV polymerase, and is polymerase substrate. Lamivudine three phosphate incorporation into viral DNA chain, can block the synthesis of viral DNA, and does not interfere with normal cell deoxynucleoside metabolism, having weak inhibition to mammalian DNA polymerase alpha and beta, almost no effect on mammalian cell DNA content, and without obvious toxicity to the structure of mitochondria, content and function of DNA. For Serum HBV-DNA detection results of most hepatitis B patients showed that lamivudine can rapidly inhibit the replication of HBV, its inhibitory effect lasted for the entire treatment process. At the same time the serum transaminase decreased to normal, long-term use can significantly improve the liver necrosis and inflammatory changes in relieve or prevent liver fibrosis.

Appearance Properties

White to white crystalline powder.

Side Effects

The following adverse reactions are often appearing, such as fatigue, headache, abdominal pain, nausea, flatulence, diarrhea and indigestion; Can produce nephrotoxicity. Therefore, when taking adefovir dipivoxil, should close observation of renal function, especially those that already exist in patients with kidney disease; Can cause blood lactic acid in the body, so that the body acid-base balance disorders, resulting in metabolic disorders; After stopping the drug, can cause hepatitis exacerbations, liver enlargement, liver area pain and so on.

matters need attention

1.Patients stop treating hepatitis B can occur acute exacerbation of hepatitis, including the cessation of the use of adefovir dipivoxil. So, stopping the treatment of hepatitis B patients should be monitored for liver function, if necessary, should reanti-hepatitis B therapy. 2. Adefovir dipivoxil has slight kidney toxicity and before taking general medicine, should check renal function,and check for many times. For patients with renal dysfunction or potential renal dysfunction risk, should closely monitor renal function and serum phosphorus changes and according to the patient's age, weight and creatinine level calculated creatinine clearance rate, and creatinine clearance rate of appropriate dose adjustments. We should avoid as far as possible taking injection or other nephrotoxic drugs at the same time. 3. The use of anti hepatitis B therapy with adefovir dipivoxil, will have an effect on the chronic hepatitis B patients, who carrying the unknown or untreated HIV, may be HIV drug resistance. Before treatment, all patients should be taken for human immunodeficiency virus (HIV) antibody test. 4. Hepatitis B patients during antiviral therapy, taking the single with nucleoside analogues or in combination with other anti retroviral drugs will lead to lactic acidosis and severe associated with steatosis of hepatomegaly, including fatal events. 5.Because the risk of developing human embryos is not clear, it is proposed that the treatment of women of childbearing age should take effective contraceptive measures. For already pregnant patients with hepatitis B should be in under the guidance of professional doctors consider to stop drug.

Treatment of chronic hepatitis B can cause severe renal dysfunction

American scholar's research shows that the treatment of adefovir dipivoxil (ADV) is an independent predictor of severe renal dysfunction in patients with chronic hepatitis B (CHB), for receiving the ADV treatment of patients with renal function monitoring, especially in the elderly, the baseline impairment of renal function or high blood pressure, diabetes patients. The study published in magazine of liver disease. ADV can cause renal dysfunction, but the occurrence rate and clinical significance are no long-term follow-up studies, nor clinical trials outside data. The study evaluate the clinical practice in ADV treatment caused the incidence and severity of renal dysfunction in patients with CHB. Two community health center of 290 cases of CHB patients were enrolled, the 145 cases of ADV (10 mg) received treatment, 145 patients did not receive ADV treatment and baseline characteristics of the two groups were similar, men accounted for 76.5%, baseline estimated glomerular filtration rate (EGFR) >50ml/min, baseline serum creatinine is 0.97~DL 0.99mg/, baseline creatinine clearance rate was 5.0~85.4ml/min. The incidence of ADV group of renal dysfunction (eGFR≤50ml/min) rate for 5 cases per 100 patients per year and the untreated group of 136 cases per 100 patients per year (P = 0.02), the relative risk is 3.68. ADV is significant predictors of risk factors of severe renal dysfunction (HR) =3.49, P = 0.03], age > 50 years old (HR=3.49, P = 0.087), baseline with mild renal impairment (HR=2.36, P = 0.074) for the 3.68.ADV, hypertension and (or) diabetes (HR=2.36, P = 0.074) and other factors increase trend of kidney damage.

Curative effect of treating chronic hepatitis B

There are at least 350 million people infected with hepatitis B virus (HBV) in the world. Hepatitis B treatment key to success is whether durable suppression of viral replication. α-interferon antiviral and immunomodulatory effects, clear effect, but its withdrawal after sustained response problems and more adverse reactions and injection therapy limits the clinical application. Adefovir dipivoxil is a new anti HBV drugs, due to less side effects of the drug, medication convenience and other advantages, so since birth it has been paid great attention. It is mainly used for the treatment of active viral, e antigen (HBeAg) positive chronic hepatitis B patients. And recently published in < New England Journal of Medicine > a report display, adefovir dipivoxil in HBeAg negative chronic hepatitis B patients were equally effective and long-term use can make curative effect has remained unchanged. In order to clarify the efficacy of chronic hepatitis B with negative e antigen and to prolong the duration of the drug, the researchers did the following experiments. Research process adopts the comparative method, the first step is that 185 HBeAg negative chronic hepatitis B patients were divided into two groups, the first group of 123 people, took adefovir dipivoxil of 10 mg/time/d; the second group of 62 people a day took the same dose of placebo, the treatment lasted for 48 weeks. The second step is after 48 weeks of treatment, received adefovir dipivoxil were randomly divided into two groups. One group continued taking, after treatment of the 96 weeks to continue treatment, and the remaining patients take placebo. Patients who taking placebo at the beginning, be substituted with adefovir dipivoxil. Results of the study showed that patients having been accepted for the treatment, medication 96 weeks and 144 weeks later, the amount of virus in the serum are significantly decreased. Treatment to the 96 week, 71% of the patients with viral levels below 1000 copies per milliliter; and after 144th week, 79% of the patients in vivo virus level below 1000 copies per milliliter. But patients after treatment of 144 weeks, have the emergence of low virus resistance. After 48 weeks, patients stopped the treatment and the therapeutic effect of most people disappeared, the virus also returned to the original level. To the 96 weeks and only 8% of patients with viral levels less than 1000 copies per milliliter, and until the 49 weeks to the 144th week, side effects are similar to the beginning of the 48 week, 144 weeks later, 5.9% of patients appear resistant mutations in the virus.

Uses

Different sources of media describe the Uses of 142340-99-6 differently. You can refer to the following data:
1. Has a broad spectrum of antiviral activity, can be used for the treatment of chronic hepatitis B.
2. Adefovir Dipivoxil(Preveon, Hepsera) works by blocking reverse transcriptase, an enzyme that is crucial for the hepatitis B virus (HBV) to reproduce in the body. It is approved for the treatment of chronic hepatitis B in adults with evidence of active vir
3. A nucleotide analog, useful as an oral reverse transcriptase inhibitor (ntRTI).

Description

Adefovir dipivoxil is the first nucleotide analog to be launched in the US as an oral treatment for hepatitis B virus (HBV) infections. It can be easily prepared in 4 steps from adenine. Adefovir dipivoxil acts as a bioavailable ester prodrug which is rapidly hydrolyzed to free adefovir and further anabolized to its active form, adefovir diphosphate, by two intracellular phosphotylation steps. The diphosphate competitively inhibits reverse transcriptase and/or causes chain termination when incorporated into growing DNA. Adefovir dipivoxil has a broad antiviral spectrum against retro-, herpes- and hepadnaviruses. The drug inhibits HBV replication, decreases HBV DNA levels and improves liver histology of patients infected with HBV wild type and resistant to other antivirals such as lamivudine. It also demonstrated activity in hepatitis B”e” antigennegative, or precore mutant, patients and in patients co-infected with HIV. To date, no adefovir dipivoxil-associated resistance mutations have been identified in patients up to 136 weeks with the drug. The oral bioavailability of adefovir after oral administration of its dipivoxil prodrug is approximately 30%. It is mainly excreted unchanged in the urine and its plasma elimination half-life is 4.2 h. However, a long intracellular half-life (17 h) of the active bisphosphorylated metabolite enables once-daily dosing. The most prominent adverse effect of adefovir dipivoxil is nephrotoxicity (which has prevented the drug from being marketed for HIV infections where the drug required administration at higher doses).

Chemical Properties

White Solid

Originator

Institute of Organic Chemistry and Biochemistry of the Academy of Sciences in the Czech Republic and the REGA Stichting Research (Czech Republic, Belgium)

Brand name

Hepsera (Gilead Sciences).

General Description

Adefovir is an orally active prodrug that is indicated for thetreatment of the chronic form of hepatitis B. The dipivoxil moieties are hydrolyzed by ubiquitous esterases to yieldadefovir, which is phosphorylated by adenylate kinase toyield adefovir diphosphate. This compound is inhibitory atHBV DNA polymerase. In addition, adefovir undergoes incorporationinto viral DNA and causes chain termination.Adefovir is poorly absorbed by the oral route, but the dipivoxilester groups cause the bioavailability to increase toapproximately 60%.

Mechanism of action

Adefovir dipivoxil is an orally active prodrug indicated for the treatment of chronic hepatitis B. The drug is hydrolyzed by extracellular esterases to produce adefovir, which in turn is phosphorylated by adenylate kinase to adefovir diphosphate, which inhibits HBV DNA polymerase. Incorporation of adefovir into viral DNA also leads to DNA chain termination. As shown in Figure 43.9, adefovir dipivoxyl is activated in two steps involving an esterase that exposes a free phosphate group (adefovir), followed by addition of a second phosphate by adenylate kinase to form adefovir diphosphate, the active form of the drug.

Clinical Use

Adefovir dipivoxil joins interferon and lamivudine in the treatment of chronic HBV. It can be used singly or in combination with lamivudine. Early clinical studies indicate benefit of the use of adefovir dipivoxil to treat lamivudine-resistant HBV with a low level of resistant virus developing to monotherapy with adefovir dipivoxil.

Synthesis

Steroidal dutasteride (5) was synthesized from 3-oxo-4- androstene-17β-carboxylic acid (55). Oxidation of 55 with potassium permanganate, sodium periodate and sodium carbonate in refluxing t-butyl alcohol and water gave secosteroid 56 which was cyclized with ammonium acetate in acetic acid to give 4-aza-steroid 57 in good yield. Stereoselective hydrogenation of 57 with H2 over PtO2 in hot acetic acid and in the presence of ammonium acetate yielded saturated azasteroid 58, which was dehydrogenated with DDQ in the presence of bis(trimethylsilyl)trifluoroacetamide (BSTFA) 59 in refluxing dioxane to give 60. Treatment of 60 with thionyl chloride gave the corresponding acyl chloride intermediate, which was then condensed with 2,5- bis(trifluoromethyl)aniline (61) by means of DMAP in heated toluene to give dutasteride (5) in 57% yield from intermediate 60.

Drug interactions

Potentially hazardous interactions with other drugs Use with caution in combination with other nephrotoxins. Antivirals: avoid concomitant administration with tenofovir Interferons: use with caution with peginterferon alfa.

Metabolism

Adefovir is poorly absorbed orally, but the bioavailability of adefovir dipivoxil reaches approximately 59%. The drug is absorbed to an equal extent with or without the presence of food. Adefovir is excreted renally unchanged.

InChI:InChI=1/C20H32N5O8P/c1-19(2,3)17(26)30-11-32-34(28,33-12-31-18(27)20(4,5)6)13-29-8-7-25-10-24-14-15(21)22-9-23-16(14)25/h9-10H,7-8,11-13H2,1-6H3,(H2,21,22,23)

Synthetic route

Chloromethyl pivalate (18997-19-8) + Adefovir (106941-25-7) → adefovir dipivoxyl (142340-99-6)

Conditions	Yield
With triethylamine In 1-methyl-pyrrolidin-2-one at 50 - 55℃; Solvent; Reagent/catalyst; Temperature; Inert atmosphere; Large scale;	78.1%
With 1,8-diazabicyclo[5.4.0]undec-7-ene In N,N-dimethyl-formamide at 25℃; for 24h;	75%
With tetrabutylammomium bromide; triethylamine In 1-methyl-pyrrolidin-2-one at 65 - 75℃; for 2h; Temperature; Reagent/catalyst; Solvent;	57.5%

[[2-chloroethoxy]methyl]phosphonic acid bis(pivaloyloxymethyl) ester + 7H-purin-6-ylamine (73-24-5) → adefovir dipivoxyl (142340-99-6)

Conditions	Yield
With potassium carbonate In N,N-dimethyl-formamide at 90 - 95℃; for 9h; Large scale;	46.18%

chloropentyl pivalate + Adefovir (106941-25-7) → adefovir dipivoxyl (142340-99-6)

Conditions	Yield
With triethylamine In 1-methyl-pyrrolidin-2-one at 30 - 60℃; for 16h; Reagent/catalyst;	32.6%

2,2-Dimethyl-propionic acid (2,2-dimethyl-propionyloxymethoxy)-[2-(6-{[(4-methoxy-phenyl)-diphenyl-methyl]-amino}-purin-9-yl)-ethoxymethyl]-phosphinoyloxymethyl ester → adefovir dipivoxyl (142340-99-6)

Conditions	Yield
With acetic acid In methanol for 12h; Ambient temperature; Yield given;

iodomethyl pivaloate (53064-79-2) → adefovir dipivoxyl (142340-99-6)

Conditions	Yield
Multi-step reaction with 2 steps 1: pyridine / 36 h / Ambient temperature 2: aq. AcOH / methanol / 12 h / Ambient temperature View Scheme

N6-(4-monomethoxytrityl)-9-(2-phosphonomethoxyethyl)adenine (153235-86-0) → adefovir dipivoxyl (142340-99-6)

Conditions	Yield
Multi-step reaction with 2 steps 1: pyridine / 36 h / Ambient temperature 2: aq. AcOH / methanol / 12 h / Ambient temperature View Scheme

N4-dimethylaminomethyledino-9-(2-phosphonomethoxyethyl)adenine di(pivaloyloxymethyl) ester (922494-99-3) → adefovir dipivoxyl (142340-99-6)

Conditions	Yield
Stage #1: N4-dimethylaminomethylideno-9-(2-phosphonomethoxyethyl)adinine di(pivaloyloxymethyl) ester With acetic acid In water at 25 - 55℃; for 3h; Stage #2: With triethylamine In water; ethyl acetate pH=7.5;
Stage #1: N4-dimethylaminomethylideno-9-(2-phosphonomethoxyethyl)adinine di(pivaloyloxymethyl) ester With water; acetic acid at 25 - 55℃; for 3h; Stage #2: With triethylamine In water; ethyl acetate pH=7.5;

Chloromethyl pivalate (18997-19-8) + Adefovir (106941-25-7) → 9-[2-({bis[(pivaloyloxy)methoxy]phosphinyl}methoxy)ethyl]-6-[(hydroxymethyl)amino]purine (323201-04-3) + adefovir dipivoxyl (142340-99-6)

Conditions	Yield
In dimethyl sulfoxide; triethylamine at 43℃; for 4h;
Stage #1: Chloromethyl pivalate; Adefovir With triethylamine In dimethyl sulfoxide at 40℃; for 5h; Stage #2: With water In dichloromethane; dimethyl sulfoxide at 10 - 20℃; for 0.0833333h; Product distribution / selectivity;

adenine (66224-66-6, 66224-67-7, 66224-68-8, 66224-69-9, 134434-48-3, 134434-49-4, 134454-76-5, 134461-75-9) → adefovir dipivoxyl (142340-99-6)

Conditions	Yield
Multi-step reaction with 3 steps 1.1: potassium carbonate / N,N-dimethyl-formamide / 1 h / 25 - 85 °C 1.2: 20 h 2.1: water; hydrogen bromide / 4 h / 90 - 95 °C 2.2: 25 - 30 °C / pH 2.8 3.1: triethylamine; tetrabutylammomium bromide / ethyl acetate; N,N-dimethyl-formamide / 1 h / 25 - 35 °C 3.2: 25 - 35 °C View Scheme
Multi-step reaction with 4 steps 1.1: sodium hydride / N,N-dimethyl-formamide / 16 h / 60 °C 2.1: ammonia / methanol / 14 h 3.1: magnesium 2-methylpropan-2-olate / N,N-dimethyl-formamide / 1 h / 20 °C / Inert atmosphere 3.2: 20 h / 35 °C / Inert atmosphere 4.1: sodium bromide; 1-methyl-pyrrolidin-2-one; chloro-trimethyl-silane / 12 h / 60 °C / Inert atmosphere 4.2: 6 h / 60 °C View Scheme
Multi-step reaction with 4 steps 1: triethylamine / acetonitrile / 14 h / 125 °C / Inert atmosphere 2: magnesium 2-methylpropan-2-olate / N,N-dimethyl-formamide / 12 h / 80 °C 3: chloro-trimethyl-silane / chlorobenzene / 10 h / 120 °C 4: triethylamine / 1-methyl-pyrrolidin-2-one / 16 h / 30 - 60 °C View Scheme

[[2-(6-amino-9H-purine-9-yl)ethoxy]methyl]phosphonic acid diethyl ester (116384-53-3) → adefovir dipivoxyl (142340-99-6)

Conditions	Yield
Multi-step reaction with 2 steps 1.1: water; hydrogen bromide / 4 h / 90 - 95 °C 1.2: 25 - 30 °C / pH 2.8 2.1: triethylamine; tetrabutylammomium bromide / ethyl acetate; N,N-dimethyl-formamide / 1 h / 25 - 35 °C 2.2: 25 - 35 °C View Scheme

Chloromethyl pivalate (18997-19-8) + [[2-(6-amino-9H-purine-9-yl)ethoxy]methyl]phosphonic acid diethyl ester (116384-53-3) → adefovir dipivoxyl (142340-99-6)

Conditions	Yield
Stage #1: [[2-(6-amino-9H-purine-9-yl)ethoxy]methyl]phosphonic acid diethyl ester With 1-methyl-pyrrolidin-2-one; chloro-trimethyl-silane; sodium bromide at 60℃; for 12h; Inert atmosphere; Stage #2: Chloromethyl pivalate With triethylamine at 60℃; for 6h;

9-(2-hydroxyethyl)adenine (707-99-3) → adefovir dipivoxyl (142340-99-6)

Conditions	Yield
Multi-step reaction with 2 steps 1.1: magnesium 2-methylpropan-2-olate / N,N-dimethyl-formamide / 1 h / 20 °C / Inert atmosphere 1.2: 20 h / 35 °C / Inert atmosphere 2.1: sodium bromide; 1-methyl-pyrrolidin-2-one; chloro-trimethyl-silane / 12 h / 60 °C / Inert atmosphere 2.2: 6 h / 60 °C View Scheme
Multi-step reaction with 3 steps 1.1: sodium hydride / N,N-dimethyl-formamide / 1 h / 5 °C / Large scale 1.2: 5 h / 5 °C / Large scale 2.1: trimethylsilyl bromide / acetonitrile / 3 h / 20 °C / Large scale 2.2: 2 h / Reflux; Large scale 3.1: triethylamine / 1-methyl-pyrrolidin-2-one / 2 h / 60 °C View Scheme
Multi-step reaction with 3 steps 1: magnesium 2-methylpropan-2-olate / N,N-dimethyl-formamide / 12 h / 80 °C 2: chloro-trimethyl-silane / chlorobenzene / 10 h / 120 °C 3: triethylamine / 1-methyl-pyrrolidin-2-one / 16 h / 30 - 60 °C View Scheme
Multi-step reaction with 3 steps 1.1: magnesium 2-methylpropan-2-olate / N,N-dimethyl-formamide / 1 h / 78 - 82 °C 1.2: 78 - 82 °C 2.1: trimethylsilyl bromide / 80 - 85 °C 3.1: triethylamine / 1-methyl-pyrrolidin-2-one / 50 °C View Scheme

benzoic acid 2-(6-amino-purin-9-yl)-ethyl ester → adefovir dipivoxyl (142340-99-6)

Conditions	Yield
Multi-step reaction with 3 steps 1.1: ammonia / methanol / 14 h 2.1: magnesium 2-methylpropan-2-olate / N,N-dimethyl-formamide / 1 h / 20 °C / Inert atmosphere 2.2: 20 h / 35 °C / Inert atmosphere 3.1: sodium bromide; 1-methyl-pyrrolidin-2-one; chloro-trimethyl-silane / 12 h / 60 °C / Inert atmosphere 3.2: 6 h / 60 °C View Scheme

6-Chloro-9-(β-hydroxyethylamino)purine (1670-62-8) → adefovir dipivoxyl (142340-99-6)

Conditions	Yield
Multi-step reaction with 3 steps 1.1: sodium hydride / tetrahydrofuran / -20 - 0 °C / Inert atmosphere 1.2: 48 h / 50 °C 2.1: trimethylhalosilane / acetonitrile / 20 °C / Inert atmosphere; Cooling with ice 3.1: N,N'-dicyclohexyl-4-morpholine carboxamidine; triethylamine / N,N-dimethyl-formamide / 12 h / 48 - 52 °C View Scheme

6-chloro-9-(ethoxycarbonylmethyl)-9H-purine (56791-59-4) → adefovir dipivoxyl (142340-99-6)

Conditions	Yield
Multi-step reaction with 4 steps 1.1: methanol; sodium tetrahydroborate / 0 °C 2.1: sodium hydride / tetrahydrofuran / -20 - 0 °C / Inert atmosphere 2.2: 48 h / 50 °C 3.1: trimethylhalosilane / acetonitrile / 20 °C / Inert atmosphere; Cooling with ice 4.1: N,N'-dicyclohexyl-4-morpholine carboxamidine; triethylamine / N,N-dimethyl-formamide / 12 h / 48 - 52 °C View Scheme

6-chloropurine (87-42-3) → adefovir dipivoxyl (142340-99-6)

Conditions

Yield

Multi-step reaction with 5 steps 1.1: scandium tris(trifluoromethanesulfonate) / acetonitrile / 0.17 h / 20 °C 2.1: methanol; sodium tetrahydroborate / 0 °C 3.1: sodium hydride / tetrahydrofuran / -20 - 0 °C / Inert atmosphere 3.2: 48 h / 50 °C 4.1: trimethylhalosilane / acetonitrile / 20 °C / Inert atmosphere; Cooling with ice 5.1: N,N'-dicyclohexyl-4-morpholine carboxamidine; triethylamine / N,N-dimethyl-formamide / 12 h / 48 - 52 °C View Scheme

maleic acid (110-16-7) + adefovir dipivoxyl (142340-99-6) → adefovir dipivoxil maleate

Conditions	Yield
In ethyl acetate at 40℃; for 3h; Temperature;	98%

adefovir dipivoxyl (142340-99-6) → C20H30(2)H2N5O8P

Conditions	Yield
With deuterium In tetrahydrofuran; cyclohexane at 55℃; under 1500.15 Torr; for 36h; Reagent/catalyst; Glovebox;	96%

saccharin (81-07-2) + adefovir dipivoxyl (142340-99-6) → adefovir dipivoxil:saccharin salt (1403836-42-9)

Conditions	Yield
In acetone at 0 - 50℃; Product distribution / selectivity;	90%
In ethanol at 25℃; for 0.166667h;

nicotinamide (98-92-0) + adefovir dipivoxyl (142340-99-6) → adefovir dipivoxil:nicotinamide cocrystal (1403836-41-8)

Conditions	Yield
In ethyl acetate at 20 - 70℃; for 25.25h; Product distribution / selectivity;	80%

adefovir dipivoxyl (142340-99-6) + salicylamide (65-45-2) → adefovir dipivoxil:salicylamide cocrystal

Conditions	Yield
In tert-butyl methyl ether; acetone at 20℃; Product distribution / selectivity; Reflux;	78%

pivaloyl chloride (3282-30-2) + adefovir dipivoxyl (142340-99-6) → bis[(2-(6-pivaloylamino-9H-purin-9-yl)ethoxy)methyl]phosphonic acid bis(pivaloyloxymethyl) ester

Conditions	Yield
With triethylamine In dichloromethane at 20℃; for 8h; Cooling with ice;	76.13%

adefovir dipivoxyl (142340-99-6) → 9-{2-[O,O'-bis(pivaloyloxymethyl)thiophosphonomethoxy]ethyl}adenine (1443213-13-5)

Conditions	Yield
With 2,4-bis(methylthio)-1,3-dithia-2,4-diphosphetane-2,4-disulfide In benzene at 0 - 80℃; for 2.5h;	29%

adefovir dipivoxyl (142340-99-6) → adefovir dipivoxil monohydrate (1110441-05-8)

Conditions	Yield
With water In dichloromethane at 20 - 25℃; for 24h;
With water for 24h;

formic acid (64-18-6) + adefovir dipivoxyl (142340-99-6) → adefovir dipivoxil formic acid

Conditions	Yield
In ethyl acetate at 20 - 40℃;

adefovir dipivoxyl (142340-99-6) → Adefovir (106941-25-7)

Conditions	Yield
With ethylenediaminetetraacetic acid; DL-dithiothreitol; water; magnesium chloride In aq. buffer at 37℃; for 1h; pH=7.5; Enzymatic reaction;

Upstream product

• 18997-19-8 Chloromethyl pivalate 
• 106941-25-7 Adefovir 
• 142341-24-0 9-<2-(phosphonomethoxy)ethyl>adenine, bis(phenyl ester) 
• 707-99-3 9-(2-hydroxyethyl)adenine 
• 116384-53-3 [[2-(6-amino-9H-purine-9-yl)ethoxy]methyl]phosphonic acid diethyl ester 
• 922494-99-3 N₄-dimethylaminomethylideno-9-(2-phosphonomethoxyethyl)adinine di(pivaloyloxymethyl) ester 
• 153235-86-0 N⁶-(4-monomethoxytrityl)-9-(2-phosphonomethoxyethyl)adenine 
• 87-42-3 6-chloropurine 
• 56791-59-4 6-chloro-9-(ethoxycarbonylmethyl)-9H-purine 
• 1670-62-8 6-Chloro-9-(β-hydroxyethylamino)purine 
• 66224-66-6 adenine 
• 73-24-5 7H-purin-6-ylamine 
• 53064-79-2 iodomethyl pivaloate 

Downstream Products

• 106941-25-7 Adefovir 

Relevant articles and documents

Preparation method of nucleoside phosphate prodrug

The invention belongs to the field of pharmaceutical chemicals, and relates to a preparation method of a nucleoside phosphate prodrug. A diphenol phosphate intermediate A and an alcohol compound B are subjected to a transesterification reaction to obtain the nucleoside phosphate prodrug. According to the method, rapid synthesis of different nucleoside prodrugs is achieved through exchange of the base-catalyzed nucleoside diphenyl phosphate intermediate and alcohol, synthesis of a target compound is achieved through one-step reaction, meanwhile, use of strong acid and high-toxicity chlorides is avoided, the safety of generation can be improved, the cost is reduced, and emission of three wastes is reduced.

Synthetic method of adefovir dipivoxil

The invention relates to the field of chemical pharmaceuticals, in particular to an industrial production and synthesis process of an adefovir dipivoxil bulk drug. 9-(2-hydroxyethyl)-adenine and diethyl p-toluenesulfonyloxymethyl phosphate serve as raw materials, and under the action of a catalyst, adefovir dipivoxil is produced through esterification, desalination and hydrolysis. The adefovir dipivoxil is subjected to acid and alkali refining, then condensed with chloromethyl valerate, then separated and purified to obtain adefovir divalentyl oxymethyl ester raw materials. The synthetic process is an industrialized production process, the operation is simple, adefovir dipivoxil is suitable for large-scale production, and the production cost can be greatly reduced.

Preparation method of adefovir dipivoxil crystals

The invention belongs to the technical field of drug preparation and in particular relates to a preparation method of adefovir dipivoxil crystals. The preparation method comprises the following steps: synthesizing diethyl phosphite; synthesizing diethyl (p-phenylsulfonyloxy)methylphosphonate; synthesizing 9-(2-hydroxyethyl) adenine; synthesizing 4,9-[2-(diethylphosphonomethoxy)ethyl]adenine; synthesizing adefovir; synthesizing adefovir dipivoxil. Compared with the prior art, the preparation method of the adefovir dipivoxil crystals, provided by the invention, takes acetonitrile as a water-soluble organic medium, and the difficulty that DMF (Dimethyl Formamide) is difficult to remove is overcome; ethyl acetate is used for replacing isopropyl acetate in a previous process, isopropyl ether is used for replacing ethyl ether and ethanol is used for replacing acetone; the preparation method is simple to operate; the obtained product has good purity and high yield; the industrialized production is easy to realize and the production cost is reduced.