4-[3-(4-chlorophenyl)-4,5-dihydro-1H-pyrazol-1-yl]benzenesulphonamide

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:

From January 22th to February 08th, 2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

test procedure in accordance with generally accepted scientific standards and described in sufficient detail

Qualifier:

according to guideline

Guideline:

OECD Guideline 102 (Melting point / Melting Range)

Version / remarks:

adopted on 27 July 1995

GLP compliance:

yes (incl. QA statement)

Type of method:

differential scanning calorimetry

Remarks:

and capillary method

Melting / freezing pt.:

225.9 °C

Atm. press.:

1 atm

Decomposition:

yes

Decomp. temp.:

347 - 390 °C

DSC ANALYSIS

At the start of the experiment, the substance appeared as a dark blue powder; at the end of the experiment the substance appeared as black powder. Initial weight of the test item found to be 2.0 mg and after analysis residue found to be 0.7 mg.

During the DSC heating up phase, an endothermic reaction was recorded between 226 to 231 °C, which can be reasonably attributed to the melting point. In the temperature range of 347 - 390 °C the substance undergoes decomposition, through a series of successive exo-endo-thermic reactions.  

Peak	Replicate	Onset (°C)	Endset (°C)	Peak (°C)	Energy (J/g)
1^stpeak (endo)	Rep. 1	226.29	231.52	229.3	111.51
	Rep. 2	226.94	230.52	228.47	109.34
Mean		226.61	231.02	228.89	110.42
2^ndpeak (exo)	Rep. 1	347.48	368.52	361.26	-53.09
	Rep. 2	355.81	361.60	359.14	-39.67
Mean		351.64	365.06	360.20	-46.38
3^rdpeak (endo)	Rep. 1	368.51	388.48	375.92	51.32
	Rep. 2	367.71	390.33	375.82	63.41
Mean		368.11	389.40	375.87	57.36

CAPILLARY TEST

Test item melt at 225.9 °C and no visual change was observed.

Conclusions:

The substance melts at ca 226 °C and then undergoes to decomposition from ca 347 °C.

Executive summary:

The thermal behaviour of the test item was determined as per OECD guideline 102, Melting Point/Melting Range. The melting point of the test item was carried out using differential scanning colourimetry method. The melting point of a test item was defined as the temperature at which phase transition from a solid to liquid state takes place at normal atmospheric pressure.

In order to confirm the DSC outcomes, an additional measurement with capillary method was performed in the temperature range of ca 25 – 250 °C. The experiment was carried out in three replications.

At the start of the experiment, the substance appeared as a dark blue powder; at the end of the experiment the substance appeared as black powder. Initial weight of the test item found to be 2.0 mg and after analysis residue found to be 0.7 mg.

During the DSC heating up phase, an endothermic reaction was recorded between 226 to 231 °C, which can be reasonably attributed to the melting point. In the temperature range of 347 -390 °C the substance undergoes decomposition, through a series of successive exo-endo-thermic reactions.  

The melting point was confirmed by the capillary test, during which the test item melt at 225.9 °C and no visual change was observed.

Conclusion

The substance melts at ca 226 °C and then undergoes to decomposition from ca 347 °C.

Description of key information

The substance melts at ca 226 °C and then undergoes to decomposition from ca 347 °C.

Key value for chemical safety assessment

Melting / freezing point at 101 325 Pa:

225.9 °C

Additional information

OECD 102 - Differential Scanning Calorimetry analysis and capillary method