Benzyl-PEG7-MS , CAS No.B1446491

CAS: B1446491 Cat. No.: B1446491 Summenformel: C₂₂H₃₈O₁₀S Molekulargewicht: 494.60

Storage

Store at -20°C

Shipped In

Ice chest + Ice pads

Übersicht

Benzyl-PEG7-MS is a PEG-based PROTAC linker that can be used in the synthesis of PROTACs.

Specifications

Storage

Store at -20°C

Verschickt in

Ice chest + Ice pads

Dieses Produkt erfordert Kühlkettenversand. Grundversand und andere Economy-Optionen sind nicht verfügbar.

Namen und Kennungen

Molekulargewicht

494.60

Application Protocols

No biological assay protocols (e.g., WB, IHC, FC, IF) apply to this small-molecule linker. For synthetic use, see Reaction Conditions and Synthetic Utility for general procedural guidance. Always adapt stoichiometry, solvent, and temperature to the specific nucleophile and substrate.

Biological Roles

No inherent biological role is assigned to Benzyl-PEG7-MS; it is a synthetic linker for research use only.

General context for PEG linkers (informational):

• PEG spacers increase aqueous compatibility, reduce nonspecific binding, and modulate steric accessibility in chemical biology probes, surface grafting, and material interfaces.
• Benzyl end-group provides an aromatic handle that can influence binding in supramolecular assemblies or facilitate spectroscopic detection (UV absorbance from the phenyl ring).
• Downstream derivatives (after substitution of the mesylate) can be used to append PEG7–benzyl segments to peptides, small molecules, nanoparticles, and surfaces to tune solubility and hydrodynamic size.
• Biocompatibility of PEG stems from low protein adsorption; however, this product is an electrophile and should not be used directly in biological systems without appropriate derivatization and purification.

Important: This product is provided strictly for research and laboratory use; it is not intended for diagnostic, therapeutic, or in vivo applications.

Buffer Applications

This product is not a buffering agent and has no defined acid–base pair for pH control. Consequently, standard buffer recipes and buffering ranges are not applicable.

Practical note (general): If conjugating in aqueous media, reactions are typically conducted in mixed organic/aqueous systems with controlled pH using compatible buffers (e.g., bicarbonate or phosphate) alongside phase-transfer catalysis. However, the mesylate functionality is susceptible to hydrolysis in water; anhydrous organic media are generally preferred for efficient substitution.

Green Alternatives

Green chemistry for reactions with Benzyl-PEG7-MS focuses on solvent choice, bases, and catalysts to reduce hazard and waste while maintaining SN2 efficiency.

• Greener solvent options (general):

  • 2-MeTHF/CPME: Bio-based ethers; good for O-/S-alkylations with inorganic bases or NaH. Water immiscible for easy workup.
  • Propylene carbonate: High-boiling, low-toxicity polar aprotic; supports halide or carbonate bases. May need elevated temperature.
  • Cyrene (dihydrolevoglucosenone): Biomass-derived dipolar aprotic; effective for some SN2 substitutions with carbonate bases.
  • Green acetonitrile alternatives: Ethyl acetate sometimes viable with PTC, though rates can be slower.

• Greener bases/catalysts:

  • Carbonates (K2CO3, Cs2CO3) over strong, pyrophoric bases when possible.
  • Tetrabutylammonium halides as phase-transfer catalysts to avoid excess polar aprotics; KI/TBAI catalytic activation can reduce temperature and time.

• Comparison (informational):

  • DMSO/DMF: High performance; regulatory and EHS concerns; challenging removal.
  • 2-MeTHF/CPME: Safer, volatile; may require longer times or higher temps for difficult nucleophiles.
  • Propylene carbonate: Very low VOC; high bp complicates solvent removal but excellent for scalable processes.

• Process tips:

  • Use solvent-recovery and minimal solvent volumes.
  • Favor room-temperature or modest heating with catalytic halide activation to lower energy input.
  • Design telescoped sequences (e.g., azide formation → click) to reduce isolations and washes.

All recommendations are general literature guidance; optimize per substrate.

Pharmaceutical Uses

No pharmacopeial status or excipient designation is provided for this item. It is supplied for research use only.

Informational context (general, not item-specific):

• PEG linkers are widely explored in discovery chemistry to improve solubility and modulate physicochemical properties of leads, as well as to construct conjugates (e.g., PEGylated probes, surfaces). Benzyl-terminated PEGs can serve as spacers in the synthesis of tool compounds or affinity resins.
• The mesylate terminus is a synthetic handle; it is typically converted to other functionalities (amines, thiols, azides) prior to any consideration of formulation research. Unreacted mesylates are reactive electrophiles and are not suitable as excipients.
• For any preclinical formulation research, residual sulfonate ester must be verified absent, and product identity/purity confirmed by appropriate analytical methods (HPLC, NMR, MS). No therapeutic or clinical use is implied.

Physical Properties

Item-specific physical constants are not provided for this catalog entry; consult the CoA/Spec Sheet for definitive specifications.

General/literature expectations for benzyl-PEGn mesylates (informational, not product specifications):

• Physical state: typically a colorless to pale yellow, viscous liquid or low-melting wax for PEG7 chain length.
• Solubility (literature/general): highly soluble in polar aprotic organics (DMSO, DMF, acetonitrile, THF, 1,4-dioxane); soluble in dichloromethane and ethyl acetate; limited miscibility with nonpolar hydrocarbons; may be miscible with water, though hydrolysis can occur—use anhydrous conditions for synthetic work.
• Polarity: intermediate-to-high due to the PEG chain; strong hydrogen bond acceptor, negligible donor capability.
• Refractive index, density, bp/mp, logP, pKa: Not specified for this item; refer to CoA/Spec Sheet. (Mesylate esters do not have meaningful pKa as electrophiles; PEG ethers have no acidic protons.)
• Hygroscopicity (general): PEGylated mesylates can be mildly hygroscopic; absorbed moisture accelerates hydrolysis to the corresponding alcohol.

Practical note: For analytical characterization, 1H NMR typically shows a benzylic singlet (~4.4–4.6 ppm, literature) and a broad PEG envelope (3.4–3.8 ppm), with mesyl methyl near ~3.0 ppm; disappearance of the mesylate methyl and shift of terminal signals can monitor substitutions (literature guidance).

Quality and Grades

• Grade/Purity: Not specified for this item; refer to CoA/Spec Sheet.

Guidance on interpreting grades for this class of products (general, not item-specific):

• Research/Screening grade: Suitable for library synthesis and discovery chemistry. Typical quality controls include NMR purity, LC-MS identity/purity, and water content (Karl Fischer). Low metal content is usually not critical for linker electrophiles unless for catalysis downstream.
• High-purity or “>95–98%” grades (when specified): Beneficial for bioconjugation and materials chemistry to minimize side reactions or oligomer distributions. For PEG linkers, distribution around n = 7 repeat units can exist unless “discrete/monodisperse” is explicitly stated.
• Stabilizers: None are typically added to PEG mesylates; if a stabilizer or inhibitor is used, it will be declared on the CoA/Spec Sheet. Absence/presence affects downstream reactivity and purification.
• Analytical controls to review on CoA:
  • Identity: 1H/13C NMR, HRMS/ESI-MS.
  • Purity: HPLC/UPLC area %, residual solvents, mesylate integrity (absence of hydrolyzed alcohol).
  • Water: Karl Fischer; low moisture preferred to prevent hydrolysis (value not provided here).
  • Appearance: Not specified for this item; refer to CoA/Spec Sheet.

Recommendation: If employing in sensitive conjugations, request lot-specific CoA for exact purity, water, and residual solvent levels before use.

Reaction and Applications

This benzyl-terminated PEG7 mesylate functions as a versatile monofunctional PEGylation linker and electrophile.

• Key transformations (general literature guidance):
  • O-alkylation: Alkoxides from alcohols/phenols displace mesylate to give R–O–(CH2CH2O)7–CH2–Ph. Bases: NaH, K2CO3, Cs2CO3. Solvents: DMF, MeCN, acetone, THF. Catalytic KI or TBAI often helpful.
  • S-alkylation: Thiolates add efficiently to afford thioethers; mild bases (K2CO3, Et3N) suffice. Useful for cysteine conjugation on small molecules and materials.
  • N-alkylation: Primary/secondary amines yield benzyl-PEG7 amines (tertiary amines or ammonium salts). Control over mono- vs di-substitution via stoichiometry and base.
  • Azide installation: NaN3 substitution to give benzyl-PEG7–N3, enabling CuAAC/SPAAC click after Staudinger or reduction steps.
  • Carbanion substitution: Soft carbon nucleophiles (e.g., malonates, cyanides) can displace under strong base/PTC.
• Applications:
  • Spacer/linker in probe design, materials, and surface modification to improve solubility, reduce aggregation, and modulate hydrodynamic radius.
  • Precursor to orthogonally functionalized PEGs (e.g., azide, thioacetate, amine) for subsequent bioconjugation.
  • Benzyl tag provides UV/fluorescence handle and potential π–π interactions in supramolecular systems.
• Practical notes:
  • Maintain anhydrous conditions; hydrolysis competes with substitution.
  • Stoichiometric base, temperature control (rt–80°C), and halide catalysis improve yields.
  • Monitor by LC-MS/NMR; disappearance of mesyl methyl signal (~3.0 ppm, literature) indicates consumption.

Reaction Conditions

General literature guidance for SN2 substitutions on PEG primary mesylates (not product specifications):

• O-alkylation of phenols/alcohols:
  • Base: K2CO3 (2–3 equiv) or Cs2CO3 (1.5–2 equiv).
  • Solvent: DMF or MeCN (0.1–0.5 M). Temperature: 50–90°C.
  • Additives: KI or TBAI (10–20 mol%) to accelerate. Time: 4–18 h.
  • Note: For sensitive substrates, use THF with NaH (1.1–1.5 equiv) at 0→rt, then warm to 40–60°C as needed.
• S-alkylation of thiols:
  • Base: K2CO3 or Et3N (1.2–2 equiv).
  • Solvent: Acetone, MeCN, or DMF. Temperature: rt–60°C. Time: 1–6 h.
  • Often proceeds rapidly; avoid excess base to limit elimination.
• N-alkylation of amines:
  • Base: DIPEA or Na2CO3 (1.5–2 equiv).
  • Solvent: MeCN, DCM, or DMF. Temperature: rt–50°C. Time: 2–12 h.
  • Control multiple alkylation via stoichiometry and slow addition.
• Azide displacement:
  • Reagents: NaN3 (2–3 equiv), catalytic NaI.
  • Solvent: DMF or DMSO. Temperature: 60–90°C. Time: 3–8 h.
• Phase-transfer option:
  • Aqueous K2CO3 or KOH with toluene/EtOAc and TBAB/TBAI (5–10 mol%). Temperature: reflux; efficient for phenolates/thiolates.

Monitoring: LC-MS or TLC with permanganate/anisaldehyde stains (PEGs may be weak by UV alone; benzyl aids detection). Prevent hydrolysis by maintaining anhydrous conditions.

Safety and Handling

Hazard classification details are not provided for this item. Always consult the product SDS for authoritative safety information.

• GHS/Signal word/Pictograms/H-statements: Not specified for this item; refer to SDS.
• Anticipated hazards (general for sulfonate esters and PEG electrophiles):
  • Irritation to skin, eyes, and respiratory tract; harmful if swallowed. Some alkyl sulfonates are potent alkylating agents—avoid exposure.
  • Hydrolysis to alcohol and methanesulfonic acid under moist conditions; the acid is corrosive.
• PPE: Wear lab coat, safety glasses or face shield, and appropriate chemically resistant gloves (e.g., nitrile). Work in a fume hood.
• Incompatibilities (general): Strong bases and nucleophiles (reactive), strong acids (decompose), moisture/water (hydrolysis), strong oxidizers (sulfonate degradation), active metals. Avoid prolonged contact with amines unless intended for reaction.
• Handling tips:
  • Use anhydrous solvents and dry glassware. Minimize headspace moisture.
  • Dispense using dry syringes/pipettes. Cap promptly. Purge with inert gas when feasible.
• First aid overview (general):
  • Skin/eye contact: Rinse with water for at least 15 minutes; remove contaminated clothing; seek medical attention.
  • Inhalation: Move to fresh air; seek medical attention if symptoms occur.
  • Ingestion: Rinse mouth; do not induce vomiting; seek medical attention.
• Waste: Collect organic sulfonate-containing waste in halogenated/non-halogenated organic streams per institutional policy. Do not release to drains.

Solvent Selection

Benzyl-PEG7-MS is a polar, aprotic electrophile. Selecting solvent influences both solubility and SN2 kinetics.

• Preferred solvents (general):
  • Polar aprotics: DMF, DMSO, NMP, acetonitrile—maximize nucleophilicity and typically dissolve both salts (with PTC) and the PEG mesylate.
  • Ethereal solvents: THF, 1,4-dioxane for less polar nucleophiles and organometallic bases; ensure anhydrous grade.
  • Chlorinated: DCM can dissolve substrate but may slow SN2; often used for reactions with soluble amines/thiols plus a non-nucleophilic base.
• Aqueous/bi-phasic systems: Possible with phase-transfer catalysts (e.g., TBAB, TBAI) for O- or S-alkylations using inorganic bases; avoid prolonged aqueous exposure to limit hydrolysis.
• Water and alcohols: Promote hydrolysis to the corresponding alcohol; avoid unless intentionally quenching.
• Solvent comparison (general guidance):
  • DMSO/DMF: Highest SN2 rates; may complicate workup but enable room-temp reactions.
  • MeCN: Good balance of rate and volatility; often effective 40–80°C.
  • THF/dioxane: Useful for base-sensitive partners; may require reflux.
  • Green options: 2-MeTHF, CPME, propylene carbonate, Cyrene—see Green Alternatives.

Tip: Add catalytic KI or TBAI to accelerate displacement (in situ iodide activation). Thoroughly dry solvents; water content strongly impacts conversion.

Storage and Reconstitution

• Storage (item-specific): Store at -20°C. Protect from moisture and light. Keep container tightly closed under inert gas where possible.
• Shipping (item-specific): Shipped in ice chest + ice pads.
• Stability (general guidance): Sulfonate esters can hydrolyze over time, especially with moisture. Open only when equilibrated to room temperature to avoid condensation. After opening, consider aliquoting under dry nitrogen/argon and resealing.
• Reconstitution and handling (general):
  • Solvents: Anhydrous DMSO, DMF, MeCN, THF, or DCM are commonly used. Prepare stock solutions immediately before use.
  • Concentration: Prepare as needed (e.g., 0.1–1.0 M) depending on application; store solutions at 4°C or −20°C for short periods if necessary, preferably under inert gas and desiccation.
  • Avoid aqueous media unless intentionally reacting under PTC conditions; water promotes hydrolysis to the corresponding alcohol and methanesulfonic acid.
• Shelf-life: Not specified for this item; refer to CoA/Spec Sheet.

Research Use Note: For research use only.

Structure and Identity

Benzyl-PEG7-MS is a benzyl-terminated, hepta(ethylene glycol) spacer bearing a terminal methanesulfonate (mesylate, –OSO2Me) leaving group. It serves as a monofunctional PEG linker for nucleophilic substitution to install a benzyl–PEG7 chain onto diverse substrates.

• Item-specific identifiers:
  • CAS: Not specified for this item; refer to CoA/Spec Sheet.
  • Molecular Formula: Not specified for this item; refer to CoA/Spec Sheet.
  • Molecular Weight: Not specified for this item; refer to CoA/Spec Sheet.
  • SMILES: Not specified for this item; refer to CoA/Spec Sheet.
  • InChIKey: Not specified for this item; refer to CoA/Spec Sheet.
• Structural features (general description):
  • One terminus: benzyl group (Ph–CH2–) providing a hydrophobic/aromatic handle.
  • Spacer: PEG7 chain comprising seven –CH2CH2O– repeat units, conferring hydrophilicity and flexibility.
  • Reactive terminus: mesylate (–OMs), a good leaving group for SN2 substitution by O-, N-, S-, or C-nucleophiles.
  • Functional group set: aryl (phenyl), benzylic methylene, multiple ethers, sulfonate ester.
  • Stereochemistry: none (acyclic PEG chain; no defined stereocenters).
• 2D structure in words (general): Phenyl ring attached to –CH2–[O–CH2–CH2]7–O–SO2–CH3; the mesylate is the electrophilic site for displacement.

Note: Exact atom count/connectivity and any minor distribution in PEG chain length should be confirmed from the item’s CoA/Spec Sheet.

Synthetic Utility

As a discrete electrophilic PEG linker, Benzyl-PEG7-MS provides a modular strategy to introduce a benzyl–PEG7 moiety onto nucleophiles with high functional group tolerance.

• Retrosynthetic value:
  • Target structures containing –X–(CH2CH2O)7–CH2–Ph (X = O, S, N, etc.) can be accessed directly via SN2 from the mesylate, avoiding multistep PEG assembly or protection–deprotection.
• Transformational versatility (general):
  • Convert to azide (NaN3) → reduce to amine → further acylation/urea/carbamate formation.
  • Convert to thioacetate (KSAc) → hydrolyze to thiol for Michael additions or disulfide chemistry.
  • Direct O-/N-alkylation of nucleophiles to install hydrophilic tethers on hydrophobic scaffolds, aiding solubility and enabling bifunctional constructs.
  • Formation of quaternary ammonium species with tertiary amines for ionic materials/surfactants.
• Selectivity and control:
  • SN2 favored at the primary mesylate terminus; minimize elimination by avoiding strong bases at high temperature.
  • Catalytic iodide (NaI/TBAI) or crown ether/PTC can dramatically enhance rates with inorganic bases.
• Workup/purification (general):
  • Typical: aqueous quench → extraction → silica or reverse-phase purification; PEGylated products may require RP chromatography or precipitation from MTBE/hexanes.
  • Remove residual iodide/halide catalysts via washes with thiosulfate or brine to prevent discoloration.

This utility summary is based on literature practices for PEG mesylates; verify conditions for each substrate.

Target Specificity

Not applicable. This product is a small-molecule PEG linker, not a biological affinity reagent or antibody. No target, epitope, clone, species reactivity, or isotype information is relevant.