70-00-8

Trifluorothymidine (70-00-8) is an analog of thymidine which inhibits thymidylate synthase possesses antiviral and anticancer activity.1,2 ?After phosphorylation by thymidine kinase, it is incorporated into DNA where it induces DNA-damage and interferes with repair enzymes.3 Enhances frame shift insertion and deletion in CRISPR genome editing in pluripotent stem cells.4

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Trifluorothymidine ,Mann,W. Germany,1975

anti-herpesvirus antiviral agent

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Trifluridine is used as antiviral agent in ophthalmie preparations.

ChEBI: A pyrimidine 2'-deoxyribonucleoside compound having 5-trifluoromethyluracil as the nucleobase. An antiviral drug used mainly in the treatment of primary keratoconjunctivitis and recurrent epithelial keratitis.

Trifluridine (Viroptic) is a fluorinated pyrimidine nucleoside that has in vitro activity against HSV-1 and HSV- 2, vaccinia, and to a lesser extent, some adenoviruses. Activation of trifluridine requires its conversion to the 5 monophosphate form by cellular enzymes.Trifluridine monophosphate inhibits the conversion of deoxyuridine monophosphate (dUMP) to deoxythymidine monophosphate (dTMP) by thymidylate synthetase. In addition, it competes with deoxythymidine triphosphate (dTTP) for incorporation by both viral and cellular DNA polymerases. Trifluridine-resistant mutants have been found to have alterations in thymidylate synthetase specificity.

A suspension of 4.00g (6.75 mmol) of 3',5'-bis-O-(p-nitrobenzoyl)-2'-deoxy-5- (trifluoromethyl)uridine in 250 ml of methanol was treated with 10 ml of diisopropylamine and refluxed until it had dissolved (about 18 minutes), and the solution was concentrated. The dry residue was partitioned between 50 ml of chloroform and 50 ml of water. The chloroform layer was washed with 20 ml of water, and the combined aqueous layers were concentrated. A low ultraviolet extinction (ε 7200 and 262 μm; pH 1) and the presence of isopropyl signals in the NMR spectrum (two singlets at γ8.73 and 8.85) indicated the dry residue contained diisopropylamine, probably as a salt with the relatively acidic heterocyclic N-H in 14.
A solution in 75 ml of water was treated with 8 ml (volume of resin) of Dowex 50 (H), prewashed with water and methanol. The resin was removed on a filter and washed with 25 ml of methanol and 50 ml of water, The combined filtrate was evaporated in vacuo to form 1.99 g of 2'-deoxy-4- (trifluoromethyl)uridine (100%), melting point 171°C to 175°C.

Viroptic (Monarch).

Antiviral (ophthalmic)

Trifluridine, 5-trifluoromethyl-29-deoxyuridine (Viroptic),is a fluorinated pyrimidine nucleoside that demonstrates invitro inhibitory activity against HSV-1 and HSV-2, CMV,vaccinia, and some adenoviruses.Trifluridine possesses atrifluoromethyl group instead of an iodine atom at the 5-position of the pyrimidine ring.
synthetase, and the biologically generated triphosphatecompetitively inhibits thymidine triphosphate incorporationinto DNA by DNA polymerase. In addition, trifluridine inits triphosphate form is incorporated into viral and cellularDNA, creating fragile, poorly functioning DNA.Trifluridine is approved in the United States for the treatmentof primary keratoconjunctivitis and recurrent epithelialkeratitis caused by HSV types 1 and 2. Topical trifluridineshows some efficacy in patients with acyclovir-resistantHSV cutaneous infections.

Trifluorothymidine. A synthetic halogenated pyrimidine nucleoside, first synthesized as an antitumor agent. It inhibits enzymes of the DNA pathway and is incorporated into both cellular and progeny viral DNA, causing faulty transcription of late messenger RNA and the production of incompetent virion protein. It does not require a viral thymidine kinase for monophosphorylation and is far less selective and more toxic than other analogs. It is active against HSV-1 and HSV-2, vaccinia virus, CMV and possibly adenovirus. When applied as a 1% ophthalmic solution, it rapidly enters the aqueous humor of HSV-infected rabbits’ eyes but is cleared within 60–90 min.
It causes sister chromatid exchange – an indicator of mutagenicity – at 0.5 mg/L in human lymphocytes and fibroblasts. It is teratogenic to chick embryos when injected directly into the yolk sac. Its principal adverse effects in humans following systemic administration include leukopenia, anemia, fever and hypocalcemia. Accordingly, it is restricted to topical ophthalmic use in HSV ocular infections. The ophthalmic 1% aqueous solution produces occasional punctate lesions; other side effects are similar to those of idoxuridine but arise less frequently.

Trifluorothymidine is a thymidine analog and is light sensitive. TFT serves as a thymidine kinase substrate to study enzyme specificity and kinetics. Incorporation of phosphorylated TFT into DNA induces damage, making it useful for DNA repair studies. TFT may also be used in the inhibition of thymidylate synthase and in screening mutant thymidine kinase gene.. It elicits antitumor activity in gastrointestinal (GI) cancers and has therapeutic potential to treat herpetic keratitis.

Trifluorothymidine is a fluorinated pyridine nucleoside structurally related to idoxuridine. It has been approved by the U.S. FDA and is a potent, specific inhibitor of replication of HSV-1 in vitro. Its mechanism of action is similar to that of idoxuridine. Like other antiherpes drugs, it is first phos-phorylated by thymidine kinase to mono-, di-, and triphosphate forms, which are then incorporated into viral DNA in place of thymidine to stop the formation of late virus mRNA and subsequent synthesis of the virion proteins.

Trifluorothymidine, when given IV, shows a plasma half-life of 18 minutes and is excreted in the urine either unchanged or as the inactive metabolite 5-carboxyuracil.

Trifluridine is administered as a topical ophthalmic solution for the treatment of primary keratoconjunctivitis and recurrent keratitis due to HSV-1 or HSV-2. It is not effective in the prophylaxis of these infections; however, it is effective in treating patients who were unresponsive or intolerant to topical idoxuridine or vidarabine.

The most frequent adverse reactions to trifluridine administration are transient burning or stinging and palpebral edema. Other adverse reactions include superficial punctate keratopathy, epithelial keratopathy, hypersensitivity, stromal edema, irritation, keratitis sicca, hyperemia, and increased intraocular pressure.
Trifluridine is mutagenic in vitro and carcinogenic and teratogenic when administered subcutaneously to animals. Topical trifluridine was not teratogenic in animal studies. Because it is applied topically in humans, the likelihood of systemic effects is low.

Trifluridine, 5-trifluoromethyl-1-(2-deoxyribofuranosyl)pyrimidin-2, 4-(1H.3H)-dione (36.1.22), is synthesized from 5-trifluoromethyluracil. This is synthesized by the following scheme. It begins with trifluoroacetone, from which the oxynitrile (36.1.16) is synthesized. Acetylation of this product gives the corresponding trifluoroacetate (36.1.16). Pyrrolysis of this compound gives trifluoromethylacrylonitrile (36.1.17). Adding to this dry hydrogen bromide in methanol solution in a process of which methanolysis of the nitrile group takes place the bromide 36.1.19 is obtained, which upon acidic hydrolysis undergoes heterocyclization to the dihydropyrimidine 36.1.20. Brominating of the obtained dihydropyrimidine with molecular bromine and subsequent dehydrobromination of the resulting product 36.1.21 on heating in dimethylformamide gives 5-trifluoromethyluracil (36.1.22). This is reacted with 2-deoxy-D-ribos-1-phosphate using the nucleoside phosphorylase enzyme, or by treating it with hyxamethyldisylazane and then with trichloromethylsilane to make 2,4- trimethylsilyloxy-5-trifluoromethyl pyrimidine (36.1.23).
Hexamethyldisilazane, which itself does not form trimethylsilyl ethers, is used because using a combination of two reagents leads to optimal yield of trimethylsilyl ethers. Reacting the resulting pyrimidine derivative with 3,5-bis-(4-nitrobenzoate)-2-deoxyribofuranosyl chloride in the presence of mercury (II) acetate makes the corresponding ditrimethylsilyloxy nucleoside, which when treated with an aqueous solution of potassium iodide to remove the protecting groups. The resulting product undergoes preliminary purification by chromatography, and then is treated with a methanol solution of diisopropylamine to remove the 4-nitrobenzoyl protection from the furanosyl part, giving the desired trifluridine.

Trifluridine (trifluorothymidine; Viroptic?) is a pyrimidine nucleoside analog. It is structurally related to 2-deoxythymidine, the natural precursor of DNA synthesis. Trifluridine is poorly absorbed by the cornea and is virostatic. Viroptic? interrupts viral replication by substituting “nonsense” pyrimidine analogues. For this reason, a competent surface immunity is necessary to resolve ocular disease, with or without antiviral therapy. A recent in vitro study in which several strains of feline herpes virus were collected from the United States and were used to infect kidney epithelial cells showed that trifluridine was more effective at lower concentrations compared with several other agents. For this reason, trifluridine was the first choice drug employed in the treatment of feline herpes virus ocular disease for many years. Because of the topical toxicity associated with use of trifluridine in cats, its popularity has diminished greatly. In many milder cases, the irritation associated with topical trifluridine is more intense then the inflammation induced by viral infection. Antiviral agents have also been used in the treatment of superficial punctate keratitis in the horse, thought to be associated with equine herpes virus-2 (EHV-2) infection of the cornea.

1) Bijnsdorp et al. (2010), Differential activation of cell death and autophagy results in an increased cytotoxic potential for trifluorothymidine compared to 5-fluorouracil in colon cancer cells; Int. J. Cancer, 126 2457 2) Temmink et al. (2010), Trifluorothymidine resistance is associated with decreased thymidine kinase and equilibrative nucleoside transporter expression or increased secretory phospholipase A2; Mol. Cancer Ther., 9 1047 3) Suzuki et al. (2011), Mode of action of trifluorothymidine (TFT) against DNA replication and repair enzymes; Int. J. Oncol., 39 263 4) Yu et al. (2015), Small molecules enhance CRISPR genome editing in pluripotent stem cells; Cell Stem Cell, 16 142