2-amino-6-methyl-1,2,4-triazolo[1,5-a]pyrimidin-5(1H)-one

Boiling point

Link to relevant study record(s)

Reference

Endpoint:

boiling point

Type of information:

experimental study

Adequacy of study:

key study

Study period:

01 September 2015 - 21 September 2015

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 103 (Boiling Point)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method A.2 (Boiling Temperature)

Deviations:

no

GLP compliance:

no

Remarks:

No formal claim. Study conducted in a facility operating to GLP.

Type of method:

differential scanning calorimetry

Key result

Atm. press.:

>= 98.7 - <= 100.8 kPa

Decomposition:

yes

Decomp. temp.:

320 °C

Remarks on result:

not determinable

Remarks:

due to thermal decomposition

Table 1 - Thermographic Data

Determination Number	Thermal Event – Major Endotherm	Thermal Event – Second Minor Endotherm
1	~320°C (593 K)	376.84 °C (650.0 K)
2	~320°C (593 K)	374.45 °C (647.6 K)
3	~320°C (593 K)	365.85 °C (639.0 K)
4	~320°C (593 K)	353.45 °C (626.6 K)
5	~320°C (593 K)	363.12 °C (636.3 K)

Assignment of the DSC thermograms was completed with the aid of observations recorded during a visual metal block apparatus evaluation of the test item. This assessment confirmed that the test item decomposed on melting. The test item was initially observed to be a beige colored powder and although some minor discoloration was observed during initial heating, as the melting temperature was approached, the test item became dark orange/brown in appearance, before melting to a black liquid.

Although the loss of a volatile fraction of the test item and/or its decomposition products was observed as heating continued; a significant solid residue was recovered following completion of each determination at 450 °C. It was therefore concluded that a definitive boiling temperature cannot be determined.

The use of manually pierced crucibles (an open system) also provided an opportunity to assess the stability of the test item in air and in an inert atmosphere (nitrogen). As decomposition was evident under both air and nitrogen atmospheres, this was most likely a thermal process, as opposed to oxidative.

Conclusions:

The test substance decomposed on melting at approximately 320 °C (593 K) and lost a volatile fraction as heating continued; however a significant solid residue was recovered following completion of each determination at 450 °C (723 K). As a result of thermal decomposition, a definitive boiling temperature cannot be determined.

Executive summary:

The study was performed to determine the boiling temperature of the test substance using OECD method 103 and EU Method A.2. 

The test substance decomposed on melting at approximately 320 °C (593 K) and lost a volatile fraction as heating continued; however, a significant solid residue was recovered following completion of each determination at 450 °C (723 K). Atmospheric pressure was in the range 98.7 to 100.8 kPa. Decomposition was observed both in air and under a nitrogen atmosphere. Therefore, due to thermal decomposition, a definitive boiling temperature cannot be determined.

Description of key information

The test substance decomposed on melting at approximately 320 °C (593 K) and lost a volatile fraction as heating continued; however a significant solid residue was recovered following completion of each determination at 450 °C (723 K). Atmospheric pressure was in the range 98.7 to 100.8 kPa. Decomposition was observed both in air and under a nitrogen atmosphere.