Boronic acid, B-(6-hydroxy-2-naphthalenyl)-

Melting point / freezing point

Administrative data

Endpoint:

melting point/freezing point

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2014

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: In accordance with OECD and EU protocol and GLP methods..

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2014

Report date:

2014

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

EU Method A.1 (Melting / Freezing Temperature)

Test guideline 2

Qualifier:

according to guideline

Guideline:

OECD Guideline 102 (Melting point / Melting Range)

GLP compliance:

yes (incl. QA statement)

Type of method:

thermal analysis

Remarks:

Metal Block Method also uses

Test material

Test material information

Constituent 1

Reference substance name:

(6-hydroxynaphthalen-2-yl)boronic acid

EC Number:

687-349-8

Cas Number:

173194-95-1

Molecular formula:

C10H9BO3

IUPAC Name:

(6-hydroxynaphthalen-2-yl)boronic acid

Test material form:

solid: particulate/powder

Remarks:

migrated information: powder

Details on test material:

- Name of test material (as cited in study report): Boronic Acid
-Chemical Name: 6-hydroxy-2-naphthaleneboronic acid
- Substance type: off white powder
- Storage condition of test material: room temperatire in the dark (08 to 14 October 2013), Approximately 4°C in the dark (onwards)

Results and discussion

Melting / freezing point

Melting / freezing pt.:

ca. 217 °C

Decomposition:

yes

Decomp. temp.:

ca. 217 °C

Any other information on results incl. tables

Thermal Analysis:

Thermograms and thermographic data for determinations 1 and 2 are shown in attachment 'Thermogram and Thermographic Data' below. The test item was determined to decompose while melting from approximately 217°C (490K).

Metal Block Method:

Observation times temperatures and test item appearances are shown in attachment 'Metal Block Method Results'. The test item was determined to decompose while melting from approximately 227°C(500K).

Applicant's summary and conclusion

Conclusions:

As a result of the low rate of enthalpy change during decomposition/melting, the onset temperature could only be approximated during thermal analysis.
The thermal analysis onset temperature has been reported as the definitive result as it represents the worst case scenario with respect to thermal stability. Also, the procedure utilized a standardized heating rate of 1 °C/min, compatible with the guidelines.

Visual assessment of the test item during the metal block evaluation confirmed that the thermal analysis endotherm at approximately 156 °C did not originate from a phase transition, but was attributed to the loss of a volatile component/impurity.

The test item, Boronic Acid was determined to decompose while melting from approximately 217°C (490 K).