Skip to main content


Reagent in peptide synthesis, has also been introduced into solid-phase synthesis.

CAS: 26198-19-6

Synonym: 6-Chloro-1-hydroxybenzotriazole dihydrate

Solutions:  Luxembourg Bio Technologies can provide various solutions of 6Cl-HOBt, per demand (15% in NMP etc.).




Molecular Formula


Molecular Weight

205.60 [gr/mol]


White to off-white crystalline powder

Storage Conditions

Store in a cool and dry place


  • 6-Cl-HOBt increases the efficiency of carbodiimode mediated reactions by generating an active ester that prone for Amidation.
  • Moreover, the process suppresses the formation of N-acylurea, which is a stable inert form of the incoming acid. The reaction, which is irreversible and consumes starting acid without generating peptide.
  • The beneficial effect of 6-Cl-HOBt is attributed to its capacity to protonate O-acylisourea, thus preventing the intramolecular reaction from occurring and shifting the reaction to form the active ester, end thereby decreasing the degree of racemization in numerous cases.
  • 6-Cl-HOBt has been introduced into solid-phase peptide synthesis. This additive is a good compromise between HOAt and HOBt in terms of reactivity and price


  • Assessment of 6Cl-HOBt-based coupling reagents in solid-phase cyclopeptide synthesis
    G. Sabatino; M. C. Alcaro; M. C. Pozo-Carrero; M. Chelli; P. Rovero; A. M. Papini Peptide Revolution: Genomics, Proteomics & Therapeutics, 2004, 49-50.
    Read Article
  • Developments in Peptide and Amide Synthesis
    F. Albericio Current Opinion in Chemical Biology 2004, 8:211–221.
    Read Article
  • Synthesis and Aminolysis of N,N-Diethyl Carbamic Ester of HOBt Derivatives
    S. N. Khattab, S. Y. Hassan, E. A. Hamed, F. Albericio, and A. El-Faham  Bull. Korean Chem. Soc. 2009Vol. 30, No. 12.
    Read Article

Request an Information or Quotation

Information Request

    Price Quote Request

      Skip to content