2-[3-[(4-amino-2-methylpyrimidin-5-yl)methyl]-4-methyl-1,3-thiazoniol-5-yl]ethyl dihydrogen diphosphate

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:

18 May 2016 - 20 Jan 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Reason / purpose for cross-reference:

reference to other study

Qualifier:

according to guideline

Guideline:

EU Method A.1 (Melting / Freezing Temperature)

Version / remarks:

adopted in 2008

Deviations:

no

Qualifier:

according to guideline

Guideline:

OECD Guideline 102 (Melting point / Melting Range)

Version / remarks:

adopted in 1995

Deviations:

no

GLP compliance:

no

Type of method:

differential scanning calorimetry

Specific details on test material used for the study:

Storage conditions: ambient temperature (10 to 30 °C)

Atm. press.:

1 013 hPa

Decomposition:

yes

Decomp. temp.:

169 °C

Results
Melting point/melting range: DSC measurement
Two DSC measurements showed a 1^st endothermal effect in the temperature range of 95 to 125 °C and a 2^nd endothermal effect in the range of 150 to 210 °C. A 3^rd endothermal effect (265 to 295 °C) was seen only in the second measurement. The onset temperature 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

Test item [mg]	Starting temperature [°C]	Final test temperature [°C]	Temperature range [°C]	Onset [°C]	Observations after the measurement
11.81	25	500	95 – 125 150 - 205	103.13 169.78	Black residue, mass loss: 50%
4.42		500	95 – 120 150 – 210 265 – 295	105.93 168.43 288.93	Black residue, mass loss: 48%
12.41		120	95 - 120	102.80	Test was caked, mass loss: 7%

 

Melting point/melting range: Capillary tube in a metal block
An additional measurement with the capillary method was carried out so as to clarify the DSC measurement results.

Table 2 – Capillary method results

Set point [°C]	Endpoint [°C]	Remarks
50	410	Start 50 °C: test item unchanged (white powder) Approx. 187 °C: test item discoloured to yellow; start melting Approx. 195 °C: turbid, yellow melt Approx. 202 °C: dark bubbles, foam formation, colour changed to orange Approx. 215 °C: dark orange, clear melt Approx. 249 °C: formation of bubbles; colour changed to amber Approx. 297 °C: colour changed to black End 410 °C: no further changes

 

Conclusion
The test item melted under decomposition starting at 169 °C. The first endothermal effect was most likely due to a partial evaporation of water of crystallization.

Description of key information

Substance melted under decomposition starting at 169 °C (OECD 102, DSC).