(6-Chloropyridazin-3-yl)methanamine: Handling & Application Protocol

(6-Chloropyridazin-3-yl)methanamine is a versatile chloropyridazine-containing primary amine building block widely employed as an intermediate in medicinal chemistry and the synthesis of biologically active heterocyclic compounds.

Product Name

(6-Chloropyridazin-3-yl)methanamine

SKU

C195457

Molecular Formula

C5H6ClN3

Molecular Weight

143.57 g/mol

Functional Groups

Primary amine (-CH2NH2) and aryl chloride on a pyridazine ring

Appearance

Typically a solid or oil; verify CoA for lot-specific data

Storage Condition

Store at 2–8 °C under inert atmosphere, protected from moisture and light

Safety and Pre-Use Precautions

(6-Chloropyridazin-3-yl)methanamine contains a reactive primary amine and an aryl chloride moiety. Prior to use, consult the Safety Data Sheet (SDS) provided by Aladdin Scientific (SKU C195457). The following general precautions apply:

• Wear appropriate personal protective equipment (PPE): nitrile gloves, safety goggles, and a laboratory coat.
• Handle in a well-ventilated fume hood to avoid inhalation of vapors or dust.
• The compound may be a skin, eye, and respiratory irritant; avoid direct contact.
• Keep away from strong oxidizers, acids, and moisture.
• Dispose of waste in accordance with local regulations for halogenated organic compounds.

Note: Specific toxicological data for this compound are limited in the open literature; review the product SDS carefully and add a review flag for any additional hazard data.

Solubility and Solution Preparation

Proper preparation of stock solutions is critical for reproducible results. Follow the steps below:

1. Solvent Selection: (6-Chloropyridazin-3-yl)methanamine is expected to dissolve in polar aprotic solvents such as dimethyl sulfoxide (DMSO) and N,N-dimethylformamide (DMF), as well as in methanol and water (due to the basic amine group). Verify solubility for your specific application before use.
2. Stock Solution Preparation:
   • Weigh the required amount of compound using a calibrated analytical balance in a tared vial.
   • Add the chosen solvent in small aliquots, vortexing or sonicating between additions until complete dissolution is achieved.
   • For aqueous solutions, adjust pH if necessary using dilute HCl or NaOH; the amine group (pKa typically 8–10 for benzylamines) will be protonated under acidic conditions, enhancing aqueous solubility.
3. Concentration: Prepare stock solutions at 10–100 mM in DMSO or other compatible solvent. Dilute to working concentrations in buffer or culture medium as required.
4. Filtration: Filter solutions through a 0.2 µm PTFE or nylon membrane filter if sterility is required for biological assays.

Important: Specific solubility values for C195457 are not reported in the current source material; experimentally verify solubility and record observations for your laboratory records.

Synthetic Applications and Reaction Protocols

(6-Chloropyridazin-3-yl)methanamine serves as a bifunctional building block in organic synthesis, offering two distinct reactive handles: the primary benzylic amine and the aryl chloride on the pyridazine ring. Representative applications include:

1. Amide Bond Formation (Acylation of the Primary Amine)

• React the compound with a carboxylic acid using standard coupling reagents (e.g., EDC/HOBt, HATU, or T3P) in DMF or DCM at room temperature.
• Add a base such as DIPEA (2–3 equivalents) to neutralize the HCl generated.
• Monitor reaction progress by TLC or HPLC; typical reaction times are 2–16 hours.
• Isolate the amide product by aqueous workup and column chromatography.

2. Nucleophilic Aromatic Substitution (SNAr) at the Aryl Chloride

• The 6-chloro substituent on the pyridazine ring is activated toward SNAr due to the electron-deficient nature of the pyridazine ring system.
• React with nucleophiles (amines, thiols, alkoxides) in the presence of base (K2CO3, Cs2CO3, or DIPEA) in polar aprotic solvents (DMSO, DMF) at 60–120 °C.
• Monitor by TLC or LC-MS; reaction times vary depending on nucleophile reactivity.

3. Transition-Metal-Catalyzed Cross-Coupling

• The aryl chloride can participate in Pd-catalyzed cross-coupling reactions (e.g., Buchwald-Hartwig amination, Suzuki-Miyaura coupling with arylboronic acids).
• Use standard Pd catalysts (Pd2(dba)3, Pd(OAc)2) with appropriate ligands (XPhos, BINAP) and base (Cs2CO3, K3PO4) in toluene or dioxane at 80–110 °C under inert atmosphere.
• Protect the amine if necessary (e.g., as Boc or Cbz carbamate) prior to cross-coupling to avoid catalyst poisoning.

Note: Reaction conditions provided are general guidelines based on analogous pyridazine chemistry. Optimize conditions empirically for your specific substrate combinations.

Storage, Stability, and Quality Control

Storage: Store (6-Chloropyridazin-3-yl)methanamine (C195457) at 2–8 °C in a tightly sealed container under an inert atmosphere (argon or nitrogen). Protect from light, moisture, and air to prevent oxidation or hydrolysis of the amine.

Stability: Primary amines on heterocyclic scaffolds can be susceptible to aerial oxidation and moisture absorption over time. Aliquot the compound into single-use portions where feasible to minimize repeated exposure to ambient conditions.

Quality Control Checks:

• Verify identity and purity using ¹H NMR, ¹³C NMR, and/or LC-MS against the Certificate of Analysis (CoA) provided with each lot.
• Check purity by HPLC (reverse-phase C18 column, UV detection at 254 nm); expected purity ≥95% (verify against CoA).
• If color change, precipitation, or unusual odor is observed, do not use the compound; contact Aladdin Scientific for assistance.

Shelf Life: Follow the expiry date stated on the product label and CoA. Specific shelf-life data for C195457 should be confirmed with Aladdin Scientific.

Frequently asked questions

What solvents are recommended for dissolving (6-Chloropyridazin-3-yl)methanamine?

Based on its structure—a basic primary amine on a pyridazine ring—this compound is expected to dissolve well in polar aprotic solvents such as DMSO and DMF, as well as in protic solvents like methanol and dilute aqueous acid. Specific solubility data should be experimentally determined and verified against the product CoA.

Can the aryl chloride in (6-Chloropyridazin-3-yl)methanamine undergo nucleophilic aromatic substitution?

Yes. The pyridazine ring is electron-deficient, which activates the 6-chloro substituent toward nucleophilic aromatic substitution (SNAr). Reactions with amines, thiols, or alkoxides in the presence of base and a polar aprotic solvent at elevated temperatures are generally feasible. Reaction conditions should be optimized for each specific nucleophile.

Do I need to protect the amine group before performing Pd-catalyzed cross-coupling on the aryl chloride?

It is advisable to protect the primary amine (e.g., as a Boc or Cbz carbamate) before performing Pd-catalyzed cross-coupling reactions, as free amines can coordinate to palladium and poison the catalyst. After the coupling step, the protecting group can be removed under standard deprotection conditions.

How should I verify the purity of (6-Chloropyridazin-3-yl)methanamine before use?

Purity can be assessed by reverse-phase HPLC (C18 column, UV at 254 nm) and confirmed by 1H NMR and LC-MS. Always compare results against the Certificate of Analysis (CoA) supplied with the specific lot from Aladdin Scientific (SKU C195457).

What are the typical applications of (6-Chloropyridazin-3-yl)methanamine in medicinal chemistry?

This compound is used as a versatile bifunctional building block in the synthesis of heterocyclic drug candidates. Its amine group allows for amide coupling, reductive amination, or sulfonamide formation, while the aryl chloride enables SNAr or cross-coupling reactions, facilitating the construction of diverse pyridazine-containing scaffolds relevant to drug discovery.

References

1. Clayden, J.; Greeves, N.; Warren, S. Organic Chemistry, 2nd ed.; Oxford University Press: Oxford, 2012. (General reference for nucleophilic aromatic substitution and amine reactivity.)
2. Johansson Seechurn, C. C. C.; Kitching, M. O.; Colacot, T. J.; Snieckus, V. Palladium-Catalyzed Cross-Coupling: A Historical Contextual Perspective to the 2010 Nobel Prize. Angew. Chem. Int. Ed. 2012, 51, 5062–5085. doi:10.1002/anie.201107017
3. Aladdin Scientific. Product Certificate of Analysis for (6-Chloropyridazin-3-yl)methanamine, SKU C195457. (Consult current lot CoA for purity, appearance, and physicochemical data.)

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