1,1'-(methylenedi-4,1-phenylene)bis(3-butylurea)

Dissociation constant

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

dissociation constant

Data waiving:

study technically not feasible

Justification for data waiving:

the study does not need to be conducted because the substance is insoluble

Justification for type of information:

The determination of the dissociation constant of HAT ISO is technically not feasible. REACh Regulation Annex IX, Sect. 7.16, Col. 2, states as follows: “7.16: Dissociation constant.: The study does not need to be conducted if: - the substance is hydrolytically unstable (half-life less than 12 hours) or is readily oxidisable in water, or - it is scientifically not possible to perform the test for instance if the analytical method is not sensitive enough.” For the determination of the dissociation constant of a substance, it is necessary to determine the hydrolysis of the substance at all. Hat ISO is found to be a substance highly insoluble in water. Therefore, the hydrolysis of HAT ISO in water is not determinable in a suitable manner. Consequently, the determination of the dissociation constant of HAT ISO is not practicable. Calculation of the Dissociation constants with the SPARC v 4.5 online calculating programme for estimation of chemical parameters showed the following results: pKa1: 0.39 pKa2: -0.81 pKa3: -3.71

Reference 2

Endpoint:

dissociation constant

Type of information:

(Q)SAR

Adequacy of study:

supporting study

Study period:

2009

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

results derived from a valid (Q)SAR model and falling into its applicability domain, with adequate and reliable documentation / justification

Qualifier:

no guideline followed

Principles of method if other than guideline:

calculation by using SPARC Performance Automated Reasoning in Chemistry (V 4.2)

GLP compliance:

not specified

Dissociating properties:

yes

No.:

#1

pKa:

0.39

Temp.:

20 °C

Remarks on result:

other: no

Conclusions:

By using SPARC Performance Automated Reasoning in Chemistry (V 4.2) the dissociation constants of HAT ISO were calculated to
pKa1 = 0.39;
pKa2 = - 0.81;
pKa3 = - 3.71;

Executive summary:

By using SPARC Performance Automated Reasoning in Chemistry (V 4.2) the dissociation constant of HAT ISO were calculated to

pKa1 = 0.39;

pKa2 = - 0.81;

pKa3 = - 3.71;

Description of key information

The determination of the dissociation constant of HAT ISO is technically not feasible.

REACh Regulation Annex IX, Sect. 7.16, Col. 2, states as follows:
“7.16: Dissociation constant.: The study does not need to be conducted if:
- the substance is hydrolytically unstable (half-life less than 12 hours) or is readily oxidisable in water, or
- it is scientifically not possible to perform the test for instance if the analytical method is not sensitive enough.”
For the determination of the dissociation constant of a substance, it is necessary to determine the hydrolysis of the substance at all. Hat ISO is found to be a substance highly insoluble in water. Therefore, the hydrolysis of HAT ISO in water is not determinable in a suitable manner. Consequently, the determination of the dissociation constant of HAT ISO is not practicable.
Calculation of the Dissociation constants with the SPARC v 4.5 online calculating programme for estimation of chemical parameters showed the following results:
pKa1: 0.39
pKa2: -0.81
pKa3: -3.71