Diammonium 5-(hexylsulfonyl)-2-{[3-methyl-2,7-dioxo-1-(3-sulfonatobenzoyl)-2,7-dihydro-3H-naphtho[1,2,3-de]heterocycle-6-yl]amino}benzenesulfonate

Dissociation constant

Administrative data

Endpoint:

dissociation constant

Study period:

08 January 2009 to 26 February 2009

Data waiving:

study technically not feasible

Justification for data waiving:

other:

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2009

Report date:

2009

Materials and methods

Test guideline

Qualifier:

no guideline followed

Deviations:

yes

Remarks:

No experimental testing was considered possible using Method 112 of the OECD Guidelines for Testing of Chemicals, 12 May 1981.

Principles of method if other than guideline:

No experimental testing was considered possible using Method 112 of the OECD Guidelines for Testing of Chemicals, 12 May 1981, due to the following reason:
• All of the dissociation constants were anticipated to be outside of the practical pH range.
Therefore, estimates were obtained using ACD/I-Lab Web Service (ACD/pKa 8.03), computer based estimation software.

GLP compliance:

yes (incl. QA statement)

Remarks:

Date of inspection: 19 August 2008; Date of signature: 04 March 2009

Test material

Test material information

Constituent 1

Details on test material:

Sponsor's identification : H-MI ammonium salt
Description : dark red solid
Batch number : MB-1
Date received : 04 December 2008
Storage conditions : room temperature in the dark

Results and discussion

Any other information on results incl. tables

Using the software, the following was obtained:

Dissociation Constant	Result	Functional Group
pKa1	-0.98±0.18	Sulphonic acid
pKa2	-1.17±0.50	Sulphonic acid
pKa3	-1.84±0.40	Tertiary amine
pKa4	-9.79±0.40	Secondary amine

Applicant's summary and conclusion

Conclusions:

No experimental testing was considered possible using Method 112 of the OECD Guidelines for Testing of Chemicals, 12 May 1981, due to the following reason:
• All of the dissociation constants were anticipated to be outside of the practical pH range.
Therefore, estimates were obtained using ACD/I-Lab Web Service (ACD/pKa 8.03), computer based estimation software.
Using the software, the results in the table below were obtained.

Executive summary:

No experimented testing was considered possible using Method 112 of the OECD Guidelines for Testing of Chemicals, 12 May 1981.

Therefore, estimates were obtained using ACD/I-Lab Web Service (ACD/pKa 8.03), computer based estimation software.

Using the software, the following results were obtained:

Dissociation Constant	Result	Functional Group
pKa1	Using the software, the following was obtained-0.98±0.18	Sulphonic acid
pKa2	-1.17±0.50	Sulphonic acid
pKa3	-1.84±0.40	Tertiary amine
pKa4	-9.79±0.40	Secondary amine