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Diss Factsheets

Administrative data

Endpoint:
dissociation constant
Type of information:
calculation (if not (Q)SAR)
Remarks:
estimation by calculation
Adequacy of study:
key study
Study period:
2020
Reliability:
1 (reliable without restriction)

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2020
Report date:
2020

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
other: other: Software: ACD/I-Lab Web service (pKa Algorithm Version: v5.0.0.184
Principles of method if other than guideline:
pKa is calculated from structural parameters. The algorithm is derived from a correlation of a large number of chemical structures with experimental pKa values.

Test material

Constituent 1
Chemical structure
Reference substance name:
(benzothiazol-2-ylthio)acetic acid
EC Number:
228-565-0
EC Name:
(benzothiazol-2-ylthio)acetic acid
Cas Number:
6295-57-4
Molecular formula:
C9H7NO2S2
IUPAC Name:
(1,3-benzothiazol-2-ylsulfanyl)acetic acid
Test material form:
solid: particulate/powder
Remarks:
migrated information: powder

Results and discussion

Dissociating properties:
yes
Dissociation constantopen allclose all
No.:
#1
pKa:
ca. 3.7
Temp.:
25 °C
No.:
#2
pKa:
ca. 1.8
Temp.:
25 °C
Remarks on result:
other: 2 (strongest base) = 1.8 ± 0.8

Applicant's summary and conclusion

Conclusions:
Result:
The pKa values of (Benzothiazol-2-ylthio)acetic acid at 25 °C are:
pKai (strongest acid): 3.7 ± 0.4
pKa2 (strongest base): 1.8 ± 0.8
Executive summary:

ACD/pKa-algorithm calculates acid-base ionization constants (pKa values) for 25 °C and zero ionic

strength in aqueous solutions. Each calculation is provided with its 95% confidence limits. The

accuracy of calculations is usually better than ±0.2 pKa units.

The structure was entered as SMILES code c12c(cccc1)N=C(SCC(=O)O)S2.

The calculation gave two pKa values for strongest acid and strongest base.

pKa1 (strongest acid) = 3.7 ± 0.4 and pKa2 (strongest base) = 1.8 ± 0.8 at 25 °C and zero ionic

strength.