4-Hydroxy-6-methoxymethylpyrimidine-2-thiol: Properties & Lab Guide

4-Hydroxy-6-methoxymethylpyrimidine-2-thiol is a bifunctionally substituted pyrimidine heterocycle bearing both a hydroxyl group and a thiol group, making it a versatile building block for medicinal chemistry, agrochemical synthesis, and heterocyclic chemistry research.

Chemical Name

4-Hydroxy-6-methoxymethylpyrimidine-2-thiol

Core Heterocycle

Pyrimidine (1,3-diazine) ring system

Key Functional Groups

Hydroxyl (C-4), thiol (C-2), and methoxymethyl (C-6) substituents

Tautomerism

Exists in equilibrium between hydroxypyrimidine and pyrimidinone tautomeric forms

Primary Research Use

Synthetic building block for heterocyclic and medicinal chemistry

Storage Recommendation

Store in a cool, dry, well-ventilated area away from light and moisture

Aladdin SKU

H182129

Chemical Identity and Structure

4-Hydroxy-6-methoxymethylpyrimidine-2-thiol is a pyrimidine derivative characterized by three distinct substituents on the six-membered diazine ring: a hydroxyl group at the 4-position, a thiol group at the 2-position, and a methoxymethyl group (–CH₂OCH₃) at the 6-position. The pyrimidine nucleus consists of a benzene-like aromatic ring in which nitrogen atoms occupy positions 1 and 3.

A defining structural feature of this compound is its propensity for tautomerism. The 4-hydroxy group and the 2-thiol group each participate in keto–enol and thiol–thione equilibria, respectively. In the solid state and in polar solvents, the compound predominantly adopts the 2-thioxo-2,3-dihydropyrimidin-4(1H)-one (pyrimidinethione–pyrimidinone) tautomeric form rather than the free hydroxyl–thiol form. Researchers should account for this tautomeric behavior when designing reactions targeting either functional group.

The methoxymethyl substituent at C-6 adds a flexible ether-linked side chain that modulates the electronic properties of the ring and provides an additional handle for further chemical modification or for influencing solubility and lipophilicity in biological studies.

Physicochemical Properties and Handling

As a thiol-bearing heterocycle, 4-Hydroxy-6-methoxymethylpyrimidine-2-thiol shares general physicochemical characteristics of its compound class. Thiol groups confer relatively low oxidation stability; exposure to air and moisture can promote disulfide bond formation or oxidation to sulfonic acid derivatives over time. For this reason, containers should be kept tightly sealed when not in use, and the reagent should be handled under inert atmosphere conditions (nitrogen or argon) when oxidation sensitivity is a concern in a specific experimental context.

The compound is expected to be a solid at room temperature, consistent with the molecular weight range and hydrogen-bonding capacity of similar pyrimidinethiol derivatives. Solubility is anticipated in polar aprotic solvents such as dimethyl sulfoxide (DMSO) and dimethylformamide (DMF), as well as in aqueous base where deprotonation of the thiol or hydroxyl group enhances dissolution.

Standard laboratory safety precautions apply: use appropriate personal protective equipment (PPE) including nitrile gloves, safety glasses, and a laboratory coat. Work in a well-ventilated fume hood given the potential for thiol-associated odor at elevated temperatures or upon prolonged exposure. Consult the Safety Data Sheet (SDS) provided by Aladdin Scientific for compound-specific hazard classifications before use.

Research and Synthetic Applications

Pyrimidinethiol and hydroxypyrimidine scaffolds occupy a prominent position in medicinal chemistry and agrochemical research. The combination of a thiol (or thione) function and a hydroxyl (or carbonyl) function on the same ring makes this class of compounds valuable for coordination chemistry, where such ligands can chelate metal ions through both sulfur and oxygen donor atoms.

In synthetic chemistry, 4-Hydroxy-6-methoxymethylpyrimidine-2-thiol can serve as a precursor for S-alkylation reactions at the thiol center, O-alkylation reactions at the hydroxyl/oxo center, or condensation reactions exploiting the activated methylene equivalents on the ring. These transformations allow access to a wide range of S-substituted or O-substituted pyrimidine analogs relevant to drug discovery programs targeting enzymes or receptors that bind pyrimidine-containing substrates.

The methoxymethyl group at C-6 distinguishes this compound from simpler pyrimidinethiol analogs and may confer additional metabolic stability or distinct binding interactions in biological systems, making it of interest for structure–activity relationship (SAR) studies. Researchers engaged in the development of antiviral, antibacterial, or enzyme-inhibitory agents may find this scaffold relevant as a starting material or intermediate.

Storage, Stability, and Quality Considerations

To preserve the integrity of 4-Hydroxy-6-methoxymethylpyrimidine-2-thiol over time, the following storage practices are recommended:

• Temperature: Store at room temperature in a cool area, or refrigerate if long-term storage is required. Avoid exposure to elevated temperatures that can accelerate decomposition or oxidation.
• Light: Protect from direct light exposure by storing in amber glassware or within a dark cabinet, as photodegradation may affect thiol-containing compounds.
• Moisture: Keep containers tightly sealed and consider desiccant storage to prevent hydrolytic or oxidative degradation facilitated by atmospheric moisture.
• Atmosphere: For extended storage or highly oxidation-sensitive applications, consider blanketing the container headspace with inert gas after each use.

Researchers should visually inspect the material before use. Any discoloration, change in physical form, or off-odor beyond that expected for a thiol compound may indicate degradation. When in doubt, re-characterize by appropriate analytical methods (e.g., HPLC, NMR, or melting point determination) before use in critical experiments.

Frequently asked questions

What tautomeric form does 4-Hydroxy-6-methoxymethylpyrimidine-2-thiol predominantly adopt in solution?

In polar solvents and the solid state, pyrimidinethiol derivatives bearing a 2-thiol and 4-hydroxyl group typically favor the thione–lactam tautomeric form (2-thioxo-pyrimidin-4(1H)-one) over the dithiol–diol form. Researchers should verify the predominant tautomer under their specific experimental conditions using NMR or other spectroscopic techniques before proceeding with reaction design.

Which solvents are suitable for dissolving 4-Hydroxy-6-methoxymethylpyrimidine-2-thiol?

Polar aprotic solvents such as DMSO and DMF are generally good choices for dissolving pyrimidinethiol compounds of this type. Aqueous alkaline solutions can also be effective due to deprotonation of the thiol or hydroxyl groups. Solubility in less polar solvents such as ethanol or methanol is possible but should be confirmed experimentally for the specific batch.

How should I handle 4-Hydroxy-6-methoxymethylpyrimidine-2-thiol to avoid oxidation of the thiol group?

Minimize exposure to air and moisture by working under an inert atmosphere (nitrogen or argon) when the application demands high thiol purity. Store containers tightly sealed with a desiccant, and consider adding an antioxidant such as a trace of ascorbic acid to stock solutions if oxidation is a concern. Always re-seal containers promptly after use.

Can 4-Hydroxy-6-methoxymethylpyrimidine-2-thiol be used as a ligand in metal coordination chemistry?

Yes, pyrimidinethiol and hydroxypyrimidine scaffolds are established ligand types in coordination chemistry. The compound's sulfur and oxygen donor atoms are capable of chelating a range of transition metal ions. However, the specific coordination geometry, stability constants, and preferred metal partners for this particular derivative have not been detailed in the supplied source material and would require experimental investigation or literature search.

What analytical methods are recommended to confirm the identity and purity of this compound before use?

Standard analytical methods applicable to this compound class include high-performance liquid chromatography (HPLC) for purity assessment, proton and carbon-13 NMR spectroscopy for structural confirmation, and mass spectrometry for molecular weight verification. Melting point determination can also serve as a rapid purity check. Consult the certificate of analysis (CoA) supplied with Aladdin product H182129 for the manufacturer's reported specifications.

References

1. Aladdin Scientific product page: 4-Hydroxy-6-methoxymethylpyrimidine-2-thiol, SKU H182129.
2. General reference on pyrimidinethiol tautomerism and coordination chemistry — specific literature citation not available in source material; textbook-level knowledge applied.
3. General heterocyclic chemistry reference on pyrimidine ring reactivity — specific citation not available in source material.

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