2-Chlorotrityl Chloride Resin, commonly abbreviated as 2-CTC resin or 2-ClTrt resin, is a highly acid-labile solid support used in Fmoc solid-phase peptide synthesis (SPPS). The reactive chlorotrityl functionality allows the first protected amino acid to be attached through its carboxyl group, while subsequent peptide elongation proceeds using standard Fmoc chemistry.

A major advantage of 2-Chlorotrityl Chloride Resin is that peptide acids can be released under substantially milder acidic conditions than are typically required for Wang resin. This makes the support particularly useful when a protected peptide fragment must be recovered with acid-labile side-chain protecting groups largely retained for subsequent ligation, cyclization, conjugation or convergent synthesis.

Product Information

Why Use 2-Chlorotrityl Chloride Resin?

The chlorotrityl linker is substantially more acid-labile than many conventional peptide-acid linkers. Protected peptide fragments can therefore be released using mild acidic cleavage systems such as low-concentration TFA or HFIP-containing mixtures, depending on the protecting-group strategy and experimental objective.

This property is especially valuable in convergent peptide synthesis, where a peptide segment must be detached from the solid support while retaining side-chain protecting groups for a subsequent solution-phase coupling or ligation step.

First Amino Acid Loading and C-Terminal Control

The first Fmoc-protected amino acid is normally immobilized through its carboxyl group onto the chlorotrityl linker. Published SPPS literature reports that the bulky trityl environment can reduce racemization during first-residue attachment and can also suppress diketopiperazine formation in susceptible short sequences.

These advantages can be particularly useful for C-terminal residues that are stereochemically sensitive during loading or for sequences susceptible to early-chain cyclization. Actual performance nevertheless depends on amino-acid identity, loading conditions, solvent, base and resin specification.

Protected Peptide Fragment Cleavage

2-CTC resin is widely selected when the objective is to obtain a side-chain-protected peptide acid. Published methods include cleavage with HFIP/DCM, dilute TFA/DCM and other mild acidic systems that can leave many Fmoc/tBu-compatible side-chain protecting groups in place.

When complete global deprotection is required instead, stronger TFA-based cleavage conditions may be used according to the peptide sequence and protecting-group scheme.

2-Chlorotrityl Resin vs Wang Resin

Both 2-Chlorotrityl Chloride Resin and Wang Resin are commonly used to prepare peptides with a C-terminal carboxylic acid.

The principal difference is linker acid lability. Wang resin is normally cleaved under relatively strong TFA conditions, whereas 2-CTC resin can release peptide acids under much milder conditions. For this reason, 2-CTC is generally the more useful choice when protected peptide fragments rather than fully deprotected final peptides are required.

Applications

2-Chlorotrityl Chloride Resin is used in routine Fmoc-SPPS, protected peptide-fragment synthesis, convergent peptide assembly, cyclic-peptide precursor preparation, ligation workflows and synthesis of peptide acids.

The resin itself is a synthetic support rather than an in vitro or in vivo assay reagent. Peptides produced using the resin may subsequently be purified and evaluated in biochemical, cellular or animal studies according to the downstream research design.

Purchasing and QC Considerations

For peptide-synthesis resins, CAS identity alone does not define performance. Researchers should also verify loading capacity, bead size or mesh, polymer crosslinking, moisture exposure and lot-specific substitution.

Moisture is particularly relevant for chlorotrityl chloride resin because hydrolysis of reactive chloride sites can reduce effective loading capacity. Lot-specific loading data should therefore be reviewed before quantitative SPPS planning.

For guidance on evaluating loading alongside sequence, support and solvent conditions, see Peptide Resin Loading in SPPS: How to Choose the Right Loading.

Product Documents

A Material Safety Data Sheet (MSDS) is available for this product to support laboratory handling, storage and safety assessment.

MSDS_2-Chlorotrityl-Chloride-Resin_AS2060

Certificates of Analysis (COAs) are batch-specific. Please contact us to request the COA for your product, and we will provide it by email.

Frequently Asked Questions

What is 2-Chlorotrityl Chloride Resin used for?

It is used primarily for Fmoc-SPPS of peptide acids and for preparation of protected peptide fragments that can be released under mild acidic conditions.

What C-terminus does 2-CTC resin produce?

After cleavage, peptides are normally obtained with a C-terminal carboxylic acid.

Why choose 2-CTC instead of Wang Resin?

2-CTC is substantially more acid-labile and is therefore preferred when a peptide must be cleaved while retaining side-chain protecting groups.

Does the CAS number define resin loading?

No. Loading capacity, mesh size and crosslinking are lot- or product-specification parameters and should be confirmed from the COA.

Related Technical Resources

Browse additional SPPS Resins for peptide acid and peptide amide synthesis.

For complete custom peptide production, see our Chemical Peptide Synthesis service.

Research Use Only.