Benzenamine, reaction products with aniline hydrochloride and nitrobenzene

Dissociation constant

Link to relevant study record(s)

Reference

Endpoint:

dissociation constant

Type of information:

calculation (if not (Q)SAR)

Remarks:

Eestimated by calculation

Adequacy of study:

key study

Study period:

2 August 2006 to 8 December 2006

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Study conducted to GLP in accordance with generally accepted scientific principles, possibly with incomplete reporting or methodological deficiencies, which do not affect the quality of the relevant results.

Qualifier:

according to guideline

Guideline:

OECD Guideline 112 (Dissociation Constants in Water)

Deviations:

yes

Remarks:

No experimental testing was possible using Method 112 of the OECD Guidelines for Testing of Chemicals, 12 May 1981, as the test material was a complex mixture that had been determined to be essentially insoluble in water.

Principles of method if other than guideline:

No experimental testing was possible using Method 112 of the OECD Guidelines for Testing of Chemicals, 12 May 1981, as the test material was a complex mixture that had been determined to be essentially insoluble in water.

GLP compliance:

yes (incl. QA statement)

Dissociating properties:

yes

No.:

#1

pKa:

ca. -2.52 - ca. -1.41

Remarks on result:

other: Estimate for when R = aniline. Temperature not reported.

No.:

#2

pKa:

ca. 6.19 - ca. 6.57

Remarks on result:

other: Estimate for when R = H. Temperature not reported.

The benzene substituted cyclic amine functional groups were estimated to have dissociation constants of 6.19 and 6.57 respectively, thus accepting protons at an acidic pH. When the additional R groups were aniline molecules, the resulting secondary amines functional groups were estimated to accept additional protons only under extremely acidic conditions, with dissociation constant estimates of -1.41 and -2.52 respectively (ACD/pKa 8.03).

Conclusions:

The benzene substituted cyclic amine functional groups were estimated to have dissociation constants of 6.19 and 6.57 respectively, thus accepting protons at an acidic pH. When the additional R groups were aniline molecules, the resulting secondary amines functional groups were estimated to accept additional protons only under extremely acidic conditions, with dissociation constant estimates of -1.41 and -2.52 respectively (ACD/pKa 8.03).

Executive summary:

No experimental testing was possible using Method 112 of the OECD Guidelines for Testing of Chemicals, 12 May 1981, as the test material was a complex mixture that had been determined to be essentially insoluble in water. However, from predictive structural information supplied by the Sponsor, estimations of the dissociation constants could be made. The benzene substituted cyclic amine functional groups were estimated to have dissociation constants of 6.19 and 6.57 respectively, thus accepting protons at an acidic pH, When the additional R groups were aniline molecules, the resulting secondary amines functional groups were estimated to accept additional protons only under extremely acidic conditions, with dissociation constant estimates of -1.41 and -2.52 respectively (ACD/pKa 8.03).

Description of key information

The benzene substituted cyclic amine functional groups were estimated to have dissociation constants of 6.19 and 6.57 respectively, thus accepting protons at an acidic pH. When the additional R groups were aniline molecules, the resulting secondary amines functional groups were estimated to accept additional protons only under extremely acidic conditions, with dissociation constant estimates of -1.41 and -2.52 respectively (ACD/pKa 8.03).

Additional information

No experimental testing was possible using Method 112 of the OECD Guidelines for Testing of Chemicals, 12 May 1981, as the test material was a complex mixture that had been determined to be essentially insoluble in water. However, from predictive structural information supplied by the Sponsor, estimations of the dissociation constants could be made. The benzene substituted cyclic amine functional groups were estimated to have dissociation constants of 6.19 and 6.57 respectively, thus accepting protons at an acidic pH, When the additional R groups were aniline molecules, the resulting secondary amines functional groups were estimated to accept additional protons only under extremely acidic conditions, with dissociation constant estimates of -1.41 and -2.52 respectively (ACD/pKa 8.03). The study was awarded a reliability score of 2 in accordance with the criteria set forth by Klimisch et al. (1997).