2-Chlorotrityl Chloride Resin

2-Chlorotrityl Chloride Resin (2-CTC resin) is a versatile, acid-labile resin used in the chemical synthesis of peptides using a Fmoc-amino acid/carboxyl-linked protocol for the solid phase immobilization of carboxylic acids, alcohols, phenols, and amines, imidazoles, and hydroxylamines^[1]. The conditions of solid phase immobilization release (resin cleavage) are achieved using 1-50% TFA in DCM containing 5% TIS, carboxylic acids can also be cleaved from this support with AcOH/TFE/DCM,0.5% TFA in DCM, or HFIP in DCM^{[2] [3]}.

2-Chlorotrityl Chloride Resin act as a temporary and reusable protecting group in facile synthesis of Fmoc-N-Me-AA-OH (150mg, see citation for protocol and condition)^[4], synthesis of cathepsin-B cleavable linkers (see citation for protocol and condition)^[5], and synthesis of linear and cyclic disulfide heptapeptides of longicalycinin A (see citation for protocol and condition)^[6].

References:
[1] Hoekstra, W J. “The 2-chlorotrityl resin: a worthy addition to the medicinal chemist's toolbox.” *Current medicinal chemistry* vol. 8,6 (2001): 715-9. doi:10.2174/0929867013373192
[2] Al Musaimi, Othman et al. “Greener Cleavage of Protected Peptide Fragments from Sieber Amide Resin.” *ChemistryOpen* vol. 11,12 (2022): e202200236. doi:10.1002/open.202200236
[3] Bollhagen, Ralf, et al. "A new reagent for the cleavage of fully protected peptides synthesised on 2-Chlorotrityl Chloride Resin." *Journal of the Chemical Society, Chemical Communications* 22 (1994): 2559-2560.
[4] Román, Tanya et al. “Protocol for Facile Synthesis of Fmoc-N-Me-AA-OH Using 2-CTC Resin as Temporary and Reusable Protecting Group.” *Methods and protocols* vol. 6,6 110. 13 Nov. 2023, doi:10.3390/mps6060110
[5] Pryyma, Alla et al. “Rapid, High-Yielding Solid-Phase Synthesis of Cathepsin-B Cleavable Linkers for Targeted Cancer Therapeutics.” *Bioconjugate chemistry* vol. 31,12 (2020): 2685-2690. doi:10.1021/acs.bioconjchem.0c00563
[6]HoushdarTehrani, Mohammad Hassan et al. “Synthesis of Linear and Cyclic Disulfide Heptapeptides of Longicalycinin A and Evaluation of Toxicity on Cancerous Cells HepG2 and HT-29.” *Iranian journal of pharmaceutical research : IJPR* vol. 17,3 (2018): 956-963. doi:10.1089/sur.2020.189

2-Chlorotrityl Chloride Resin（2-CTC树脂）是一种用途广泛的酸不稳定树脂，用于化学合成多肽，使用fmoc氨基酸/羧基连接方案，用于固相固定羧酸、醇、酚、胺、咪唑和羟胺^[1]。固相固定释放（树脂裂解）的条件是在含有5% TIS的DCM中使用1-50% TFA，也可以用AcOH/TFE/DCM，0.5% TFA在DCM中，或HFIP在DCM^[2,3]中裂解羧酸。

2-Chlorotrityl Chloride Resin在Fmoc-N-Me-AA-OH （150mg，方案和条件见引用）^[4]、cathepsin-B可切割连接体（方案和条件见引用）^[5]和长alycinin a线性和环二硫七肽（方案和条件见引用）^[6]的快速合成中作为临时和可重复使用的保护基团。