(4,5,6,7-Tetrahydropyrazolo[1,5-a]pyrazin-2-yl)methanol: Lab Protocol

(4,5,6,7-Tetrahydropyrazolo[1,5-a]pyrazin-2-yl)methanol is a bicyclic heterocyclic building block featuring a hydroxymethyl handle that enables versatile downstream functionalization in medicinal chemistry and drug-discovery workflows.

Product Name

(4,5,6,7-Tetrahydropyrazolo[1,5-a]pyrazin-2-yl)methanol

SKU

M730314

Core Scaffold

Bicyclic pyrazolo[1,5-a]pyrazine (partially saturated)

Key Functional Group

Primary alcohol (hydroxymethyl) at C-2 position

Primary Application

Medicinal chemistry scaffold; synthetic building block for drug discovery

Storage Recommendation

Store in a cool, dry place away from light and moisture; follow supplier SDS guidelines

Compound Overview and Structural Features

(4,5,6,7-Tetrahydropyrazolo[1,5-a]pyrazin-2-yl)methanol (Aladdin SKU: M730314) belongs to the pyrazolo[1,5-a]pyrazine family of fused bicyclic nitrogen heterocycles. The compound consists of a five-membered pyrazole ring fused to a six-membered piperazine-like ring in which the 4,5,6,7-positions are fully saturated. A primary hydroxymethyl (–CH₂OH) group is appended at the C-2 position of the pyrazole ring, providing a handle for further chemical elaboration.

This scaffold combines the conformational rigidity of a fused ring system with the synthetic versatility of a primary alcohol. The secondary amine within the saturated ring can participate in amide coupling, reductive amination, or alkylation reactions, while the hydroxymethyl group can be oxidized, esterified, etherified, or converted to a leaving group for nucleophilic substitution. These attributes make the compound a valuable sp³-rich building block for medicinal chemists seeking to explore three-dimensional chemical space.

Safety, Handling and Storage Protocol

Personal Protective Equipment (PPE): Wear appropriate laboratory PPE including nitrile gloves, a laboratory coat, and safety glasses when handling this compound. Work in a well-ventilated fume hood whenever weighing or dissolving the material to minimize inhalation exposure to fine particulates or vapors.

Storage Conditions: Store the compound in a tightly sealed container in a cool, dry location away from direct light and sources of moisture. Follow all storage instructions specified on the Certificate of Analysis (CoA) and Safety Data Sheet (SDS) provided by Aladdin Scientific. Improper storage may lead to degradation of the hydroxymethyl-bearing heterocycle, particularly through oxidation or moisture-induced decomposition.

Waste Disposal: Dispose of all chemical waste in accordance with applicable local, regional, and national regulations. Do not pour chemical waste into municipal drains. Consult your institution's Environmental Health and Safety (EHS) office for guidance on proper disposal procedures for nitrogen-containing heterocyclic compounds.

First Aid: In case of skin or eye contact, rinse immediately with copious amounts of water for at least 15 minutes and seek medical attention if irritation persists. For inhalation exposure, move to fresh air immediately. Refer to the product SDS for comprehensive first-aid measures.

Solution Preparation Protocol

Solubility Considerations: (4,5,6,7-Tetrahydropyrazolo[1,5-a]pyrazin-2-yl)methanol contains both a polar hydroxymethyl group and a basic nitrogen within the saturated ring, suggesting reasonable solubility in polar protic solvents such as water, methanol, and ethanol, as well as polar aprotic solvents such as DMSO and DMF. Empirical solubility testing is recommended for each application.

Stock Solution Preparation:

1. Allow the sealed vial to equilibrate to room temperature before opening to prevent moisture condensation on the solid.
2. Weigh the required amount of compound using a calibrated analytical balance.
3. Transfer to an appropriately sized clean, dry flask or vial.
4. Add the chosen solvent (e.g., DMSO or methanol) gradually with gentle mixing or sonication until complete dissolution is achieved.
5. Verify dissolution is complete by visual inspection. If turbidity persists, brief sonication (1–2 min) or gentle heating may be applied.
6. Filter through a 0.2 µm PTFE or nylon syringe filter if particulate-free solutions are required for biological assays.

Concentration Verification: Confirm stock concentration by UV-Vis spectrophotometry or ¹H NMR if critical precision is required. Store stock solutions under inert atmosphere (e.g., argon or nitrogen) at –20 °C for extended stability; avoid repeated freeze-thaw cycles.

Synthetic Applications and Reaction Protocol

(4,5,6,7-Tetrahydropyrazolo[1,5-a]pyrazin-2-yl)methanol is a multifunctional building block that can be engaged in a variety of synthetic transformations. The two principal reactive sites are the primary alcohol and the secondary amine of the saturated piperazine-like ring.

Amide Coupling via the Secondary Amine: The ring nitrogen can be acylated using standard amide coupling reagents (e.g., HATU, EDC/HOBt) in the presence of a tertiary amine base (e.g., DIPEA, TEA) in DMF or DCM. Reactions are typically conducted at room temperature for 12–18 hours.

Oxidation of the Hydroxymethyl Group: The primary alcohol can be oxidized to the corresponding aldehyde using Dess-Martin periodinane (DMP), Swern oxidation conditions, or TEMPO/NaOCl systems under mild conditions, enabling access to the aldehyde for further Wittig, reductive amination, or condensation chemistry.

Esterification and Etherification: The hydroxymethyl group may be esterified under standard Fischer conditions or acylated using acid chlorides/anhydrides in the presence of a base. Etherification can be accomplished via Mitsunobu reaction or alkylation of the alkoxide.

General Reaction Tips: Monitor reactions by TLC or LC-MS. The basic nitrogen may require Boc protection prior to reactions sensitive to nucleophilic amines. Deprotection with TFA in DCM (20–50% v/v) is straightforward and high-yielding for Boc removal.

Quality Control and Analytical Characterization

Each lot of (4,5,6,7-Tetrahydropyrazolo[1,5-a]pyrazin-2-yl)methanol from Aladdin Scientific (SKU: M730314) is supplied with a Certificate of Analysis (CoA) confirming identity and purity. Researchers should verify the CoA upon receipt and perform in-house quality checks as appropriate for their application.

Recommended Analytical Methods:

• ¹H NMR / ¹³C NMR: Confirms the structural identity of the compound. Characteristic signals include the pyrazole ring proton, the methylene protons of the hydroxymethyl group (–CH₂OH), and the protons on the saturated piperazine ring carbons.
• LC-MS: Provides molecular weight confirmation and purity assessment simultaneously. Use a reverse-phase C18 column with aqueous acetonitrile gradient containing 0.1% formic acid for electrospray ionization (ESI) analysis.
• HPLC (UV detection): Quantitative purity assessment; typical detection wavelength 210–254 nm.
• Karl Fischer Titration: Recommended to determine water content if moisture-sensitive downstream reactions are planned.

If the material shows unexpected color change, clumping, or altered physical appearance compared to the CoA description, contact Aladdin Scientific technical support and do not use the material until clarified.

Frequently asked questions

What solvents are recommended for dissolving (4,5,6,7-Tetrahydropyrazolo[1,5-a]pyrazin-2-yl)methanol?

Based on its polar functional groups (primary alcohol and basic ring nitrogen), this compound is expected to dissolve well in polar solvents such as DMSO, DMF, methanol, ethanol, and water. We recommend empirically testing solubility at your target concentration before committing to a large-scale preparation. If solubility is insufficient in aqueous media, adding a co-solvent such as DMSO may improve dissolution.

How should I protect the secondary amine during functionalization of the hydroxymethyl group?

The secondary amine in the saturated ring can be protected as a Boc carbamate by treatment with di-tert-butyl dicarbonate (Boc₂O) in the presence of a base such as TEA or DMAP in DCM or THF. After completing the desired transformation at the hydroxymethyl group, the Boc group is cleanly removed with TFA (20–50% v/v) in DCM at room temperature. This orthogonal protection strategy allows selective manipulation of either functional group.

What is the significance of the pyrazolo[1,5-a]pyrazine scaffold in drug discovery?

Pyrazolo[1,5-a]pyrazine and its partially saturated analogues are recognized sp3-rich bicyclic scaffolds that appear in kinase inhibitor programs and other medicinal chemistry campaigns targeting CNS and oncology indications. The partially saturated ring system improves aqueous solubility and three-dimensionality relative to fully aromatic analogues, potentially improving ADMET properties. The hydroxymethyl substituent provides a synthetic handle that enables rapid analogue synthesis via parallel chemistry approaches.

What analytical techniques confirm the identity and purity of M730314?

Identity is best confirmed by ¹H NMR and ¹³C NMR, which reveal characteristic signals for the pyrazole ring proton, the –CH₂OH methylene, and the saturated ring protons. LC-MS simultaneously confirms molecular weight and provides a chromatographic purity profile. HPLC with UV detection at 210–254 nm can give a quantitative purity value. Aladdin Scientific provides a CoA for each lot; researchers should cross-check supplied data with in-house measurements for critical applications.

References

1. Aladdin Scientific Product Page: (4,5,6,7-Tetrahydropyrazolo[1,5-a]pyrazin-2-yl)methanol, SKU M730314.
2. March, J. Advanced Organic Chemistry: Reactions, Mechanisms, and Structure. Wiley-Interscience. (General reference for alcohol and amine transformations cited in synthetic applications section.)
3. Lipinski, C. A. et al. Experimental and computational approaches to estimate solubility and permeability in drug discovery and development settings. Adv. Drug Deliv. Rev. 2001, 46, 3–26. doi:10.1016/S0169-409X(00)00129-0

Products are supplied for research and development use only. Not for use in humans, animals, diagnosis, or therapy.