3-Fluor-4'-(trans-4-propylcyclohexyl)-1,1'-biphenyl-4-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:

04.07.-16.08.2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EU Method A.1 (Melting / Freezing Temperature)

GLP compliance:

no

Type of method:

differential scanning calorimetry

Key result

Melting / freezing pt.:

>= 80 - <= 305 °C

Atm. press.:

1 013 hPa

Decomposition:

yes

Decomp. temp.:

260 °C

Remarks on result:

other: The last step was accompanied by a beginning decomposition.

Two DSC measurements with a heating rate of 10 K/min showed overall four endothermal effects in the temperature ranges of 80 - 120 °C, 125 - 210 °C, 260 - 305 °C and 440 - 485 °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.

Table 1: Melting point (DSC measurements)

Ident No.	Test item/ mg	Starting temperature / °C	Final test temperature / °C	Temperature range (endothermal) /°C	Onset (melting) / °C	Crucible	Observations after the measurement
36350	13.52	25	500	80 - 120 130 - 210 260 - 295 440 - 485	multistage 162.4 278.3 447.9	Aluminium with a hole	Test item was a black solidified melt
36501	16.49	25	320	85 - 120 125 - 210 265 - 305	multistage 163.08 291.50	Aluminium with a hole	White melt Mass loss 7 %

 

A additional measurement with the capillary method was performed to clarify the DSC measurement results. 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.

Table 2: Results of the capillary method

No.	Set point/°C	Heating rate/ K/min	Endpoint/ °C	Remarks
1	60	10	300	Approx. 174 °C: test item begins to melt Approx. 186 °C: test item partly melted, forming a single white particle Approx. 285 °C: test item melted (clear liquid), weak formation of bubbles Above 285 °C: no further change (test item fully melted)

 

Under consideration of the results from the DSC measurements and the capillary method it was concluded that the test item melted in several steps from 80 °C to 305 °C. The last step was accompanied by a beginning decomposition.

Conclusions:

The substance melted in several steps from 80 °C to 305 °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.

The test item showed three endothermal effects. The first observed to begin at 80 °C in the DSC measurement (optical observation: no effect was observed). The second effect was observed with an onset temperature of 163 °C in the DSC measurement (optical observation: start of melting at 174 °C). At the third endothermal effect occurring at 260 - 305 °C in the DSC measurement complete melting with a mass loss of 7 % was observed (optical observation: melting as well as a weak formation of bubbles). The last endothermal effect was therefore already accompanied by decomposition.

 

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.

The test item showed three endothermal effects. The first observed to begin at 80 °C in the DSC measurement (optical observation: no effect was observed). The second effect was observed with an onset temperature of 163 °C in the DSC measurement (optical observation: start of melting at 174 °C). At the third endothermal effect occurring at 260 - 305 °C in the DSC measurement complete melting with a mass loss of 7 % was observed (optical observation: melting as well as a weak formation of bubbles). The last endothermal effect was therefore already accompanied by decomposition.