(4'-methyl-3-fluoro[1,1'-biphenyl]-4-yl)-boronic acid

Melting point / freezing point

Link to relevant study record(s)

Reference

Endpoint:

melting point/freezing point

Type of information:

experimental study

Adequacy of study:

key study

Study period:

15.-16.08.2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 102 (Melting point / Melting Range)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method A.1 (Melting / Freezing Temperature)

Version / remarks:

2008

Deviations:

no

GLP compliance:

no

Type of method:

differential scanning calorimetry

Key result

Melting / freezing pt.:

>= 230 - <= 237 °C

Atm. press.:

1 013 hPa

Decomposition:

no

Two DSC measurements with a heating rate of 10 K/min showed two endothermal effects in the temperature range of 100 - 195 °C and 195 - 250 °C . The onset temperature (see Table 1) was derived from the intersection of the tangent line with the highest slope of the endothermal peak with the baseline. The first DSC measurements additionally showed an exothermal effect in the temperature range of 370 - 500 °C. The results of the DSC measurements are summarized in Table 1.

Table 1: Melting point (DSC measurements)

Ident No.	Test item/ mg	Starting temperature / °C	Final test temperature / °C	Temperature range (melting) / °C	Onset / °C	Crucible	Observations after the measurement
36492	12.28	25	500	100 - 190 190 - 250	Multistage 235.7	Aluminium with a hole	Black residue
36497	11.93	25	300	105 - 195 220 - 250	Multistage 233.2	Aluminium with a hole	Test item was a clear melt

 

A additional measurement with the capillary method was performed to clarify the results of the DSC measurements. Since this measurement was performed only as a verifying screening a high heating rate of 10 K/min was chosen and therefore the absolute temperature values derived with the capillary method are not as accurate as the DSC results. The filling height of the test item was approximately 5 mm.

The results are summarized in Table 2.

Table 2: Results of the capillary method

No.	Set point/°C	Heating rate/ K/min	Endpoint/ °C	Remarks
1	100	10	260	Approx. 140 °C: test item appeared amorphous but solid Approx. 230 °C: test item started melting Approx. 223 °C: test item was a complete clear melt

 

The capillary method measurement showed that the test item melted within a temperature range and was melted completely at 237°C.

Under the consideration of the results from the thermal stability (ambiguous onset), the DSC measurements and the capillary method it was concluded that the test item melted within a range of 230 - 237 °C.

Conclusions:

Under the consideration of the results from the thermal stability (ambiguous onset), the DSC measurements and the capillary method it was concluded that the test item melted within a range of 230 - 237 °C.

Executive summary:

A study was conducted according to OECD test guideline 102, Regulation (EC) No 440/2008 method A.1. The melting range was determined by differential scanning calorimetry. The test item and the reference are heated up from the starting temperature to the final temperature at a constant heating rate in a defined atmosphere (nitrogen). Open crucibles are used as containers for the test item and as empty reference crucible. The quantity of heat absorbed or released is measured and recorded. A measurement with the capillary method was performed to clarify the results of the DSC measurements.

Under the consideration of the results from the thermal stability (ambiguous onset), the DSC measurements and the capillary method it was concluded that the test item melted within a range of 230 - 237 °C.

Description of key information

A study was conducted according to OECD test guideline 102, Regulation (EC) No 440/2008 method A.1. The melting range was determined by differential scanning calorimetry. The test item and the reference are heated up from the starting temperature to the final temperature at a constant heating rate in a defined atmosphere (nitrogen). Open crucibles are used as containers for the test item and as empty reference crucible. The quantity of heat absorbed or released is measured and recorded. A measurement with the capillary method was performed to clarify the results of the DSC measurements.

Under the consideration of the results from the thermal stability (ambiguous onset), the DSC measurements and the capillary method it was concluded that the test item melted within a range of 230 - 237 °C.