Article · Wikipedia archive · Last revised Jun 5, 2026

PyBOP

PyBOP is a reagent used to prepare amides from carboxylic acids and amines in the context of peptide synthesis. It can be prepared from 1-hydroxybenzotriazole and a chlorophosphonium reagent under basic conditions. It is a substitute for the BOP reagent that avoids the formation of the carcinogenic waste product HMPA. Thermal hazard analysis by differential scanning calorimetry (DSC) shows PyBOP is potentially explosive.

Last revised
Jun 5, 2026
Read time
≈ 2 min
Length
346 w
Citations
6
Source
Wikipedia ↗
PyBOP
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Ball-and-stick model of the component ions of PyBOP
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Names
IUPAC name
(Benzotriazol-1-yloxy)tripyrrolidinophosphonium hexafluorophosphate
Other names
PyBOP
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.125.168
UNII
  • InChI=1S/C18H28N6OP.F6P/c1-2-10-18-17(9-1)19-20-24(18)25-26(21-11-3-4-12-21,22-13-5-6-14-22)23-15-7-8-16-23;1-7(2,3,4,5)6/h1-2,9-10H,3-8,11-16H2;/q+1;-1 checkY
    Key: VIAFLMPQBHAMLI-UHFFFAOYSA-N checkY
  • InChI=1/C18H28N6OP.F6P/c1-2-10-18-17(9-1)19-20-24(18)25-26(21-11-3-4-12-21,22-13-5-6-14-22)23-15-7-8-16-23;1-7(2,3,4,5)6/h1-2,9-10H,3-8,11-16H2;/q+1;-1
    Key: VIAFLMPQBHAMLI-UHFFFAOYAY
  • F[P-](F)(F)(F)(F)F.n4nn(O[P+](N1CCCC1)(N2CCCC2)N3CCCC3)c5ccccc45
Properties
C18H28F6N6OP2
Molar mass 520.401 g·mol−1
Appearance White crystals
Melting point 150 °C (302 °F; 423 K)
Hazards
Occupational safety and health (OHS/OSH):
Main hazards
 Irritant
GHS labelling:12
GHS07: Exclamation mark
Warning
H315, H319, H335
P261, P305+P351+P338
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
☒N verify (what is checkY☒N ?)

PyBOP (benzotriazol-1-yloxytripyrrolidinophosphonium hexafluorophosphate) is a reagent used to prepare amides from carboxylic acids and amines in the context of peptide synthesis.3 It can be prepared from 1-hydroxybenzotriazole and a chlorophosphonium reagent under basic conditions.4 It is a substitute for the BOP reagent that avoids the formation of the carcinogenic waste product HMPA.5 Thermal hazard analysis by differential scanning calorimetry (DSC) shows PyBOP is potentially explosive.6

See also

See also

References

References

  1. Sigma-Aldrich Co., product no. {{{id}}}.
  2. GHS: Sigma-Aldrich377848
  3. Mansour, Tarek S.; Bardhan, Sujata; Wan, Zhao-Kui (2010). "Phosphonium- and Benzotriazolyloxy-Mediated Bond-Forming Reactions and Their Synthetic Applications". Synlett. 2010 (8): 1143–1169. doi:10.1055/s-0029-1219820. ISSN 0936-5214.
  4. Hoffmann, Frank; Jäger, Lothar; Griehl, Carola (2003). "Synthesis and Chemical Constitution of Diphenoxyphosphoryl Derivatives and Phosphonium Salts as Coupling Reagents for Peptide Segment Condensation". Phosphorus, Sulfur, and Silicon and the Related Elements. 178 (2): 299–309. doi:10.1080/10426500307942. ISSN 1042-6507.
  5. Coste, J.; Le-Nguyen, D.; Castro, B. (1990). "PyBOP®: A new peptide coupling reagent devoid of toxic by-product". Tetrahedron Letters. 31 (2): 205. doi:10.1016/S0040-4039(00)94371-5.
  6. Sperry, Jeffrey B.; Minteer, Christopher J.; Tao, JingYa; Johnson, Rebecca; Duzguner, Remzi; Hawksworth, Michael; Oke, Samantha; Richardson, Paul F.; Barnhart, Richard; Bill, David R.; Giusto, Robert A.; Weaver, John D. (2018-09-21). "Thermal Stability Assessment of Peptide Coupling Reagents Commonly Used in Pharmaceutical Manufacturing". Organic Process Research & Development. 22 (9): 1262–1275. doi:10.1021/acs.oprd.8b00193. ISSN 1083-6160.